Aquificae
The aquific bacteria (Aquificae) are a phylum that groups together a diverse collection of bacteria that live in warm environments. They have been found in hot springs, sulphurous pits, and oceanic hydrothermal vents. Members of the genus Aquifex, for example, thrive at temperatures of 85-95 °C. They are the most abundant organisms in hot terrestrial springs from neutral to alkaline and at temperatures above 60ºC and are also found in acidic marine hydrothermal vents. They are chemosynthetic, or more precisely chemolithoautotrophs, primary carbon fixers in these habitats. They are true bacteria (domain Bacteria) as opposed to the other inhabitants of extreme environments, Archaea.
Classification
Taxonomy
There is currently no consensus regarding the taxonomy of genera within the Aquificae. A standard text [1] Archived 2012-04-14 at the Wayback Machine claims that only the genera Aquifex, Calderobacterium, Hydrogenobacter and Thermocrinis belong to the order Aquificales. Other sources consider that, in addition to the genera included in the families Aquificaceae and Hydrogenothermaceae, the genera of the Desulfurobacteriaceae family should be included in Aquificae: Balnearium, Desulfurobacterium and Thermovibrio and incertae sedis (unclassified) group EX-H1.
Phylogeny
Based on rRNA analysis, the aquatic families are related as follows:
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Relationships
Aquificae may be the oldest and most divergent group among all bacteria, as seen in phylogenetic analysis of 16S and 23S rRNA, with a chemosynthetic metabolism reminiscent of archaea. However, other genomic and protein analyzes show that the Aquificae could be related to other thermophilic groups such as Thermotoga or Thermodesulfobacteria, or approach Epsilonproteobacteria.
According to 21% of the phylogenetic trees, the aquaificals would be closely related to the ε-proteobacteria, as for example observed in the phylogenetic analysis of individual protein sequences such as the transcription elongation factor. However, this is not consistent with rRNA analysis, protein analysis, and whole genome information, in which closeness of Aquificae to Thermotogae was observed at the level of deep bacterial phylogeny.
External links and references
- ↑ All-Species Living Tree Project."16S rRNA-based LTP release 111 (full tree)". Silva Comprehensive Ribosomal RNA Database [3]. Retrieved 2013-03-20
- ↑ Cheryl P. Andam & J. Peter Gogarten 2011. Biased gene transfer in microbial evolution. Figure 1 --Δ Phylogenetic analysis of bacterial tyrosyl-tRNA synthetase amino acid sequences and the corresponding concatenated 16S–23S ribosomal RNA phylogeny. Nature Reviews Microbiology 9, 543-555 doi:10.1038/nrmicro2593
- ↑ Henz, Stefan R. et al. 2004. Whole-genome prokaryotic phylogeny. Oxford Journals Life Sciences " Mathematics " Physical Sciences Bioinformatics Volume 21, Issue 10Pp. 2329-2335.
- ↑ Christian Rinke et al. 2013. Figure 2: Maximum-likelihood phylogenetic inference of Archaea and Bacteria. Nature 499, 431–437 (25 July 2013) doi:10.1038/nature12352
- ↑ Griffiths, E. and Gupta, R. S. (2004) Signature sequences in diverse proteins provide evidence for the late divergence of the order Aquificales. International Microbiol 7: 41-52.
- ↑ Oshima K, Chiba Y, Igarashi Y, Arai H, Ishii M. (2002) Phylogenetic position of aquificales based on the whole genome sequences of six aquificales species. Int J Evol Biol. 2012;2012:859264. doi:10.1155/2012/859264
Wikispecies has an article on Affects.- Reysenbach A-L, Phylum BI (2001) Acquificae phy. nov. In: Boone DR, Castenholz RW (eds) Bergey’s Manual of Systematic Bacteriology. Springer-Verlag, Berlin, 2nd edn., pp. 359-367
- Eubacteria classification from Iziko
- Taxonomic subtree (breakable link available on the Internet Archive; see history, first version and last). from the Max Planck Society for the Advancement of Science
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Data: Q597831
Multimedia: Affects / Q597831- Species: Affordable (Bacteria)