Deltaproteobacteria
Desulfovibrio vulgaris
The Deltaproteobacteria (also δ - Proteobacteria ) form a class of the phylum (strain ) of the Proteobacteria in the phylogenetic system of the bacteria, which have been prepared on the basis of the base sequence of the 16S ribosomal ribonucleic acid. All representatives of this tribe are gram- negative.
Physiology and Ecology
Compared to other classes of the Proteobacteria, the δ - Proteobacteria are physiologically more homogeneous: To include nearly all sulfate-reducing bacteria in this group. Many academics are therefore without oxygen viable and especially in the sediment of lakes, common in the seabed or in swamps and bogs. The classic foul odor caused by hydrogen sulfide ( H2S), the sulfate-reducing bacteria produce oxidized sulfur compounds in chemical reduction. During aerobic living organisms such as plants, animals and most fungi oxygen to water reduce (O2 4 {H} → 2 H 2 O) may sulfate sulfur compounds, in particular sulfate, use as an electron acceptor: SO42 - 8 {H} H → HS - 4 H2O. The delta proteobacteria lead so from central functions in the natural sulfur cycle. With their metabolism they reduce the sulfate formed by geochemical processes or bacterial sulfide and sulfur oxidation to H2S again.
Important genera
In addition to the sulfate-reducers are among the Deltaproteobacteria also some of the most unusual bacteria: Bdellovibrio example, relies on a single bacterium hunting to other bacteria. Myxobacteria, however, are able to equal to a pack of wolves cooperatively to overwhelm other bacteria and to feed on them. If the food source is exhausted, myxobacteria form multicellular fruiting bodies complicated and resistant spores. They are the most complex of all known bacteria and stand on the threshold of multicellularity. Other important genres of Deltaproteobacteria are Desulfovibrio and Geobacter.
System
The Deltaproteobacteria are the orders:
- Bdellovibrionales Garrity et al. 2006
- Desulfarculales Corrig. Küver et al. 2006
- Desulfobacterales Küver et al. 2006
- Desulfovibrionales Küver et al. 2006
- Desulfurellales Küver et al. 2006
- Desulfuromonadales Corrig. Küver et al. 2006
- Myxococcales Tchan et al. 1948
- Syntrophobacterales Küver et al. 2006
And many have not yet been securely placed isolates.