HIERARCHICAL CLASSIFICATION OF THE PHYLUM THERMOBACTERIA
| ARCHAEA> EURYARCHAEOTA> THERMOBACTERIA |
PHYLUM THERMOBACTERIA LINKS
| TAXONOMY OF THE PHYLUM THERMOBACTERIA. This system follows that of Garrity et al. (2001 and 2003) who place the thermoplasmas in the Euryarchaeota as a taxon equal to the methanogens and halophiles. |
- CLASS THERMOCOCCI
- Cells spherical (though variable in shape), often in pairs or clustered. Motile with one or more polar flagella (Figure 1). Strict anaerobes; sulfur respiration. 80-103C. One order: THERMOCOCCALES
- Thermococcus, Pyrococcus.
- Cells spherical (though variable in shape), often in pairs or clustered. Motile with one or more polar flagella (Figure 1). Strict anaerobes; sulfur respiration. 80-103C. One order: THERMOCOCCALES
- CLASS ARCHAEGLOBI
- Cells cocci to very irregular; Strict anaerobes. Sulfate, sulfite, thiosulfate and nitrate promote growth. Elemental sulfur inhibits growth. One order: ARCHAEGLOBALES.Although extreme thermophiles (thermal optima between 64 and 92C), they differ from the other members of this phylum in the ability to reduce sulfate and generate methane. Indeed, 16S rRNA studies suggest that this group may be more closely allied with the Methanobacteria. The class has 1 order (Archaeoglobales).
- Archaeglobus, Ferroglobus.
- Cells cocci to very irregular; Strict anaerobes. Sulfate, sulfite, thiosulfate and nitrate promote growth. Elemental sulfur inhibits growth. One order: ARCHAEGLOBALES.Although extreme thermophiles (thermal optima between 64 and 92C), they differ from the other members of this phylum in the ability to reduce sulfate and generate methane. Indeed, 16S rRNA studies suggest that this group may be more closely allied with the Methanobacteria. The class has 1 order (Archaeoglobales).
- CLASS METHANOPYRI
- Rod-shaped cells; Gram +; strict anaerobes. They use hydrogen to reduce carbon dioxide. Growth above 100C; no growth below 80C. One order: METHANOPYRALES.
- These organisms have only been recognized recently as members of the extreme thermophiles. Garrity et al. (2001) recognize this as a separate group with a single order (Methanopyrales).
- Methanopyrus.
| LITERATURE CITED Black, J. G. 2002. Microbiology, Principles and Explorations. 5th ed. John Wiley and Sons, Inc. New York. Gao, B. and R. S. Gupta. 2007. Phylogenetic analysis of proteins that are distinctive of Archaea and its main subgroups and the origin of methanogenesis. BMC Genomics. 8:86. http://www.biomedcentral.com/1471-2164/8/86. Garrity, G. M., M. Winters, and D. Searles. 2001. Bergey’s manual of systematic bacteriology. 2nd ed. Springer-Verlag. New York. Garrity, G. M., J. A. Bell, and T. G. Lilburn. 2003. Taxonomic Outline of the Prokaryotes. Bergey’s Manual of Systematic Bacteriology. 2nd edition. Release 4.0. Springer-Verlag. New York. pp. 1-397. Margulis, L. and K. Schwartz. 1988. Five kingdoms, an illustrated guide to the phyla of life on earth. 2nd Edition. W. H. Freeman and Co. New York. Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Co. New York. Woese, C. R. and G. E. Fox. 1977. Phylogenetic structure of the prokaryotic domain: the primary kingdoms. Proceedings of the National Academy of Sciences USA. 74:5088-5090. Woese, C. R., O. Kandler, and M. L. Wheelis. 1990. Towards a natural system of organisms: Proposal for the domains Archaea, Bacteria, and Eucarya. Proc. Natl. Acad. Sci. USA. 87: 4576-4579. |
| By Jack R. Holt. Last revised: 02/05/2012 |
