DESCRIPTION OF THE KINGDOM FIRMICUTAE (GIBBONS AND MURRAY 1978)
| EUBACTERIA> FIRMICUTAE |
KINGDOM FIRMICUTAE LINKS
| Firmicutae (fur-ma-KU-te) is derived from the Latin root, firmus, which means strong or durable. The reference is to the relatively strong nature of the Gram positive walls of this group. |
| INTRODUCTION TO THE KINGDOM FIRMICUTAE These organisms are known as the Gram positive (text with tooltip) A Gram + cell retains the blue-black crystal-violet color following destaining with alcohol during the Gram Stain procedure. bacteria . This is a reference to how they appear after the Gram stain procedure, defined by the Danish Biologist, Hans Gram in 1884. Gram positive cells stain purple while Gram negative (text with tooltip) A Gram - cell loses the blue-black crystal-violet color following destaining with alcohol during the Gram Stain procedure. Then, it takes on the color of the counterstain, typically iodine. cells stain pink. This qualitative method for characterizing bacteria has a basis in morphology of the wall in Eubacteria. All Gram positive bacteria have the same type of bacterial wall: plasmalemma with peptidoglycan to the outside. There is no outer membrane as in the typical Gram negative taxa. Indeed, the Mycoplasmas, which seem to be simplified clostridia, have no outer wall at all. The kingdom is diverse and includes endospore (text with tooltip) Endospores are produced within the bounds of the parent cell. forming bacteria, lactic acid bacteria (and their relatives), most of the cocci (text with tooltip) A coccus (cocci, pl.) is a spherical cell form. (aerobic and anaerobic), coryneform bacteria, the actinomycetes, and the mycoplasmas. In general, this follows the system of Margulis and Schwartz (1998) who group the gram positive taxa together in a subkingdom Firmicutes with five phyla. More recent molecular evidence (e.g. Daubin et al. 2002) suggests that the gram positive taxa form two separate clades: high G-C taxa (>55% G-C in their DNA) and low G-C (<50% G-C in their DNA). The All Species Living Tree Project (Yarza et al. 2008 and 2010; Munoz et al. 2011) suggests that the systematics of the Gram positive bacteria is a mess. In their analyses, even the Bacilli (Endosporobacteria) and Clostridia (Anoxybacteria) are polyphyletic. Furthermore, Deinococci and Actinobacteria are not even in their group. Even the systematics of the Mycoplasmas (Aphragmabacteria) is unsettled. Given the current state of chaos in our understanding of the Firmicutes, we have elected to keep the gram positive taxa together as a tentative kingdom with five phyla having questionable relationships. |
FIGURE 1. Relationships between the kingdoms of Eubacteria that we use in this system. Phyla of the Firmicutes are in the shaded box. This tree uses Margulis and Schwartz (1998), with modifications from Garrity et al. (2001, 2003, and 2005), Tudge (2000), and Black (2002) in its structure. Note that the topology is very different from that of the All Species Living Tree Project (Yarza et al. 2008 and 2010; Munoz et al. 2011; see Figure 2).
FIGURE 2. A simplified summary tree for the Eubacteria adapted from the All Species Living Tree Project (Yarza et al. 2008 and 2010; Munoz et al. 2011). Note the sister relationship between the Cyanobacteria and the Firmicutes. Also, note that Actinobacteria and Deinococci are far removed from the Firmicutes.
| PHYLA OF THE KINGDOM FIRMICUTAE |
APHRAGMABACTERIA (Margulis and Schwartz 1982)
ANOXYBACTERIA (Margulis and Schwartz 1988)
ENDOSPOROBACTERIA (Margulis and Schwartz 1998)
ACTINOBACTERIA (Margulis 1974)
DEINOCOCCOBACTERIA (Margulis and Schwartz 1998)
| 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. Daubin, V. M. Gouy, and G. Perrière. 2001. Bacterial molecular phylogeny using supertree approach. Genome Informatics. 12: 155-164. 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. Gibbons, N. E. and R. G. E. Murray. 1978. Proposals concerning the higher taxa of bacteria. International Journal of Systematic Bacteriology. 28: 1-6. Gram, H. C. 1884. Über die isolierte Färbung der Schizomyceten in Schnitt- und Trockenpräparaten (in German). Fortschritte der Medizin. 2: 185–9. Margulis, L. 1974. Five-kingdom classification and the origin and evolution of cells. Evolutionary Biology. 7: 45-78. Margulis, L. and K. Schwartz. 1982. Five kingdoms, an illustrated guide to the phyla of life on earth. 1st Edition. W. H. Freeman and Co. New York. 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. 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. |
| By Jack R. Holt. Last revised: 02/11/2013 |
