DESCRIPTION OF THE PHYLUM THERMOBACTERIA1
| ARCHAEA> EURYARCHAEOTA> THERMOBACTERIA |
PHYLUM THERMOBACTERIA LINKS
| Thermobacteria (ther-mo-bak-TE-re-a) is derived from two words that mean “hot” (θερμός -hot) and “little stick” (bakterion -βακτήριον). The name is a reference to their high thermal requirement. |
| INTRODUCTION TO THE THE THERMOBACTERIA The thermobacteria is a diverse group of variable taxa that have growth maxima often at 80C or higher and differ from the thermoacidophils in that they have cell walls and have growth maxima near neutral pH. In general, the thermobacteria are unicellular (usually coccoid) and motile (Figure 1). They respire sulfur and are common members of the microbial flora of sulfotara. We have grouped together three classes that might be quite distinct. Indeed, the analyses of Gao and Gupta (2007) and Yarza et al. (2008 and 2010) suggest that they belong to separate phyla with only Thermococci remaining in the Thermobacteria. Thus, We present the following system with much qualification. These taxa had been classified in the Crenarchaeota by Margulis and Schwartz (1999); however, we have followed Garrity et al. (2001 and 2003), who place the these organisms in within the Euryarchaeota. We have followed the relative placement of Garrity et al. (2001, Figure 2) and moved them into the Kingdom Euryarchaeota together with the methanogens and extreme halophiles. |
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| FIGURE 1. TEM micrograph of Thermococcus that illustrates a tuft of polar flagella coming from a spherical cell. Image from http://www.biologie.uni-regensburg.de/Mikrobio/Thomm/Buttons/bilder/thermococcus-ch-Pt.jpg |
FIGURE 2. The relationships between the classes of the Thermobacteria (in shaded box) relative to other taxa in the Archaea.
C = CRENARCHAEOTA
E = EURYARCHAEOTA
Eu = EURYTHERMEA CLADE
Ne = NEOBACTERIA
| 1. This name is of our invention and refers to taxa that are Euryarchaeota, have cell walls, and are extreme thermophiles. |
| FURTHER READING: DISCOVERY OF THE DOMAINS OF LIFE DESCRIPTION OF THE KINGDOM EURYARCHAEOTA DESCRIPTION OF THE KINGDOM CRENARCHAEOTA |
| 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: 09/05/2016 |
