R.Sphaeroides

Rhodobacter sphaeroides
The bacterium Rhodobacter sphaeroides, shown here undergoing cell division, belongs to the subdivision… This group of bacteria are among the most metabolically diverse organisms known, being capable of growing in a wide variety of growth conditions. For example, R. sphaeroides possesses an extensive range of energy acquiring mechanisms including photosynthesis,lithotrophy, aerobic and anaerobic respiration. It can also fix molecular nitrogen; synthesize important tetrapyrroles, chlorophylls, heme, and vitamin B12.
It has extremely facile methodologies for genetic manipulations, gene transfer, genetic analyses, chromosomal mobilization, etc. In addition, R. sphaeroides 2.4.1 has been shown to detoxify a number of metal oxides and oxyanions and is the subject ofongoing (en marcha) studies on bioremediation. R. sphaeroides 2.4.1 is also the first free living bacterium known to utilize the regulatory systems associated with quorum-sensing. Other recent findings reveal that the methods of motility and environmental sensing in relation to bacterial taxis, and movement in R. sphaeroides, are unique both genetically and physiologically. This organism alsopossesses a number of traits and characteristics which show interesting similarities to those of the mammalian mitochondrion.

There are several natural isolates of R. sphaeroides, and most of those currently identified as R. sphaeroides appear to possess TWO CHROMOSOMES. The R. sphaeroides 2.4.1 genome consists of two circular chromosomes, chromosome I (CI, ~3.0 Mbp), chromosome II (CII, ~0.9Mbp), and five other replicons.
- The alignments of the HindIII and EcoRI consensus optical maps with corresponding in silico maps. (A) The outer three rings show the alignment of the in silico EcoRI optical map (outermost ring) with the chromosome I in silico maps (7 total; numbered), while the inner three circles show the alignment of the HindIII optical map (the outer one) with the chromosome Iin silico HindIII maps. The numbers indicate the sequence contig number. L1, L2, L3, and L4 indicate the four loci for adjacent sequence contigs. Orange arrows denote false cuts, red arrows denote missing cuts, and light blue arrows denote missing fragments (missing fragments less than 1 kb, or one of the two fragments for missing cuts and false cuts were not shown). (B) The outer two rings showthe alignment of the EcoRI in silico map with the corresponding optical map (the outermost ring) of chromosome II, while the inner two rings show the alignment of the HindIII in silico map with the HindIII optical map (outer). Orange arrows denote false cuts, red arrows denote missing cuts, and light blue arrows denote missing fragments (missing fragments less than 1 kb, or one of the two fragmentsless than 1 kb for missing cuts and false cuts are not shown).

- Swimming patterns of various R. sphaeroides strains in stab tubes with 0.25% agar. The tubes were incubated with constant illumination for 36 h (A), 3 days (B), 7 days (C), and 10 days (D). The strains used were WS8 (wild type), SS1 (flhA2: uidA-aadA), SP18 (flgC1::kan), and SS2 (flgC1::kan flhA2: uidA-aadA).
- Electronmicroscopy images of the two different types of flagella assembled by R. sphaeroides. (A) Representative (gancho) hook-filament structure found in the WS8 strain. (B) Representative hook-filament structure found in the SP18 fla2+ strain. (C) Intertwined (entrelazados) filaments frequently found in preparations of the SP18 fla2+ strain. (D) Representative strain WS8 cell showing a subpolar flagellum. (E)Representative strain SP18 fla2+ cell showing several polar flagella. The bars in panels A and B indicate the hook.
* The processes by which organisms use simple inorganic substances such as gaseous or dissolved carbon dioxide and inorganic nitrogen as nutrient sources. Contrasts with heterotrophic processes which make use of organic materials as the nutrient supply source. Autotrophs can be...