Epsilonproteobacteria

Epsilonproteobacteria

Epsilonproteobacteria are a class of Proteobacteria.[1] All species of this class are, like all Proteobacteria, Gram-negative.

The Epsilonproteobacteria consist of few known genera, mainly the curved to spirilloid Wolinella spp., Helicobacter spp., and Campylobacter spp. Most of the known species inhabit the digestive tracts of animals and serve as symbionts (Wolinella spp. in cattle) or pathogens (Helicobacter spp. in the stomach, Campylobacter spp. in the duodenum).

Numerous environmental sequences and isolates of Epsilonproteobacteria have also been recovered from hydrothermal vents and cold seep habitats. Examples of isolates include Sulfurimonas autotrophica,[2] Sulfurimonas paralvinellae,[3]Sulfurovum lithotrophicum[4] and Nautilia profundicola.[5] A member of the class Epsilonproteobacteria occurs as an endosymbiont in the large gills of the deepwater sea snail Alviniconcha hessleri.[6]

The Epsilonproteobacteria found at deep-sea hydrothermal vents characteristically exhibit chemolithotrophy, meeting their energy needs by oxidixing reduced sulfur, formate, or hydrogen coupled to the reduction of nitrate or oxygen.[7] Autotrophic Epsilonproteobacteria use the reverse Krebs cycle to fix carbon dioxide into biomass, a pathway originally thought to be of little environmental significance. The oxygen sensitivity of this pathway is consistent with their microaerophilic or anaerobic niche in these environments, and their likely evolution in the Mesoproterozoic oceans,[8] which are thought to have been sulfidic with low levels of oxygen available from cyanobacterial photosynthesis.[9]

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [10] and National Center for Biotechnology Information (NCBI)[11] and the phylogeny is based on 16S rRNA-based LTP release 106 by 'The All-Species Living Tree' Project [12]


  Nautiliaceae

Thioreductor micantisoli Nakagawa et al.2005



Caminibacter Alain et al.2002



Lebetimonas acidiphila Takai et al.2005


Nautilia Miroshnichenko et al.2002






Nitratiruptor tergarcus Nakagawa et al.2

  Campylobacterales

Hydrogenimonas thermophila Takai et al.2004



?Sulfuricurvum kujiense Kodama and Watanabe 2004


?Thiovulum majusHinze 1913




Nitratifractor salsuginis Nakagawa et al.2005


Sulfurovum lithotrophicum Inagaki et al.2004



Sulfurimonas Inagaki et al.2003 emend. Takai et al.2006



  Helicobacteraceae

Wolinella Tanner et al.1981


Helicobacter Goodwin et al.1989 emend. Vandamme et al.1991


  Campylobacteraceae

?Candidatus Thioturbo danicus Muyzer et al. 2005


Arcobacter Vandamme et al.1991 emend. Vandamme et al.1992



Sulfurospirillum Schumacher et al.1993 emend. Luijten et al.2003


Campylobacter Sebald and Véron 1963 emend. Vandamme et al.2010








Notes:

  • Prokaryotes where no pure (axenic) asses are isolated or available, i.e. not cultivated or can not be sustained in culture for more than a few serial passages

References

  1. ^ "www.ncbi.nlm.nih.gov". Retrieved 2009-03-19. 
  2. ^ Inagaki, F. (2003-11-01). "Sulfurimonas autotrophica gen. nov., sp. nov., a novel sulfur-oxidizing -proteobacterium isolated from hydrothermal sediments in the Mid-Okinawa Trough". INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 53 (6): 1801–1805.  
  3. ^ Takai, K. (2006-08-01). "Sulfurimonas paralvinellae sp. nov., a novel mesophilic, hydrogen- and sulfur-oxidizing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent polychaete nest, reclassification of Thiomicrospira denitrificans as Sulfurimonas denitrificans comb. nov. and emended description of the genus Sulfurimonas". INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 56 (8): 1725–1733.  
  4. ^ Inagaki, Fumio; Ken Takai; Kenneth H. Nealson; Koki Horikoshi (2004-09-01). "Sulfurovum lithotrophicum gen. nov., sp. nov., a novel sulfur-oxidizing chemolithoautotroph within the ε-Proteobacteria isolated from Okinawa Trough hydrothermal sediments". International Journal of Systematic and Evolutionary Microbiology 54 (5): 1477–1482.  
  5. ^ Julie L. Smith, Barbara J. Campbell, Thomas E. Hanson, Chuanlun L. Zhang & S. Craig Cary (2008). "Nautilia profundicola sp. nov., a thermophilic, sulfur-reducing epsilonproteobacterium from deep-sea hydrothermal vents".  
  6. ^ Yohey Suzuki, Takenori Sasaki, Masae Suzuki, Yuichi Nogi, Tetsuya Miwa, Ken Takai, Kenneth H. Nealson & Koki Horikoshi (September 2005) ) from the Indian OceanProvannidae: Gastropoda (hessleri aff. Alviniconcha and the Hydrothermal-Vent Gastropod EpsilonproteobacteriaNovel Chemoautotrophic Endosymbiosis between a Member of the . Applied and Environmental Microbiology, 71(9): 5440-5450.
  7. ^ Takai, Ken; et al. (2005). "Epsilonproteobacteria"Enzymatic and genetic characterization of carbon and energy metabolisms by deep-sea hydrothermal chemolithoautotrophic isolates of (PDF). Applied and Environmental Microbiology 71 (11): 7310–7320.  
  8. ^ Campbell, Barbara J.; Annette Summers Engel; Megan L. Porter; Ken Takai (2006-05-02). "The versatile ε-proteobacteria: key players in sulphidic habitats". Nature Reviews Microbiology 4 (6): 458–468.  
  9. ^ Anbar, A. D.; A. H. Knoll (2002-08-16). "Proterozoic Ocean Chemistry and Evolution: A Bioinorganic Bridge?". Science 297 (5584): 1137–1142.  
  10. ^ J.P. Euzéby. "Epsilonproteobacteria".  
  11. ^ Sayers; et al. "Epsilonproteobacteria".  
  12. ^  

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