DESCRIPTION OF THE KINGDOM PROTEOBACTERIAE (STACKENBRANDT ET AL. 1988)
| EUBACTERIA> PROTEOBACTERIAE |
KINGDOM PROTEOBACTERIAE LINKS
| Proteobacteriae (pro-te-o-bak-TE-re-e) is derived from two Greek roots meaning “changeable” (proteakos -πρωτεϊκός) “little stick” (bakterion -βακτήριον). The name is in reference to Proteus, the name of a Greek sea god who could change his shape (Stackebrandt et al. 1988). |
| INTRODUCTION TO THE KINGDOM PROTEOBACTERIAE Stackebrandt et al. (1988), using 16S rRNA sequences, defined a seemingly unrelated group of eubacteria as Proteobacteria, the purple bacteria, which they defined as a class that they called Proteobacteria. Within that group, they defined five separate lines, each defined by a Greek letter: α, β, γ, δ, ε. The second edition of Bergey’s Manual of Systematic Bacteriology (Garrity et al. 2003) adopted Proteobacteria, but raised it to phylum level with each of the five groups becoming classes. In order to bring the prokaryotes into line with kingdom-level divisions in the eukaryotes, I felt that it was necessary to raise the Proteobacteria to kingdom-level status with each of the five groups also raised to the level of phylum. The purple bacteria is the largest and most diverse of the microbial kingdoms. The alpha, beta, and gamma groups have many taxa that are phototrophic (text with tooltip) Phototrophs utilize light energy to provide metabolic energy. Sometimes this energy is stored asreduced organic compounds (food). , but most are chemolithotrophs (text with tooltip) Chemolithotrophs are autotrophs (make their own food) by using inorganic sources for energy and reducing power to fix carbon dioxide into food. or chemoorganotrophs (text with tooltip) Chemoorganotrophs utilize organic sources for energy and food production. . The delta and epsilon groups have no phototrophic taxa. The interpretation is that phototrophy is primitive in this line. Also, oxidative metabolism seems to have evolved several times in this kingdom. The structure of this kingdom is under intense scrutiny because there are so many taxa that are of great economic importance, both as necessary symbionts and important pathogens. Furthermore, the microbial endosymbiont that gave rise to the ancestral mitochondrion likely came from among the rickettsia (Alphaproteobacteria). Now, there is evidence emerging to suggest a sixth line that Emerson et al. (2007) refer to as “Zetaproteobacteria”. After Munoz et al. (2011) there seem to be two lines of Proteobacteria, which may be independent of each other (see the Eubacterial cladogram). |
FIGURE 1. Cladogram showing the two major clades of the Proteobacteria from Gupta (2000) and Munoz et al. (2011).
| PHYLA OF THE PROTEOBACTERIAE |
ALPHAPROTEOBACTERIA (Garrity et al. 2006)- BETAPROTEOBACTERIA (Garrity et al. 2006)
GAMMAPROTEOBACTERIA (Garrity et al. 2005)
DELTAPROTEOBACTERIA (Kuever et al. 2006)
EPSILONPROTEOBACTERIA (Garrity et al. 2006)
| FURTHER READING: DISCOVERY OF THE DOMAINS OF LIFE INTRODUCTION TO THE DOMAIN EUKARYA DESCRIPTION OF THE DOMAIN ARCHAEA |
| LITERATURE CITED Black, J. G. 2002. Microbiology, Principles and Explorations. 5th ed. John Wiley and Sons, Inc. New York. Brock, T. D., M.T. Madigan, J.M. Martinko, and J. Parker. 1994. Biology of Microorganisms. 7th ed. Prentice Hall. Englewood Cliffs, NJ. Emerson, D., J. A. Rentz, T. G. Lilburn, R. E. Davis, H. Aldrich, C. Chan, and C. L. Moyer. 2007. A novel lineage of Proteobacteria involved in formation of marine Fe-oxidizing microbial mat communities. PLoS ONE. 2007 (8): e667. http://www.plosone.org 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. 3nd Edition. W. H. Freeman and Co. New York. Tudge, C. 2000. The Variety of Life, A Survey and a Celebration of all the Creatures That Have Ever Lived. Oxford University Press. 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: 02/20/2013 |
