Non-sulfur purple bacteria

Neunlist, S., Bisseret, P., and Rohmer, M. (1988) The hopanoids of the purple non-sulfur bacteria Rhodopseudomonas palustris and Rhodopseudomonas acidophila and the absolute configuration of bacteriohopanetetrol. Eur. J. Biochem. 171, 245-252. 

Purple non-sulfur bacteria Rhodobacter Rhodocyclus Rhodomicrobium Rhodopseudomonas Rhodopila RhodospiriUum Unicellular rods, spheres, spirals... 

When purple non-sulfur bacteria switch from photosynthesis in the light to respiration in the dark, the content of BChl a or is diminished, and the synthesis of cytochrome oxidase is increased [101]. In some bacteria, such as Rb. sphae-roides, two oxidases are formed, Cyt aa [90] and Cyt o. In most others (e.g. R. rubrum) only Cyt o is formed [97]. Work during the past decade has revealed a strong similarity between the electron transfer pathways in purple non-sulfur bacteria and in the mitochondrial inner membrane [92]. 

Many photosynthetic purple bacteria are closely related phylogenetically to nonphotosynthetic respiring eubacteria. Some photosynthetic eubacteria are autotrophic (e.g. green and purple sulfur bacteria), while others are mainly hetero-trophic (e.g. filamentous bacteria, purple non-sulfur bacteria and H. chlorum). All convert light energy into chemical free energy. 

NAD" photoreduction in chromatophores isolated from several purple non-sulfur bacteria [41,48-50] and from the purple sulfur bacterium Chromatium vinosum [51] but did not inhibit ATP-driven NAD reduction in the dark. 

As indicated in Sections 1 and 2, succinate is an electron donor widely utilized for NAD(P) reduction by phototrophic purple bacteria. The membrane-bound enzyme responsible for succinate oxidation has been solubilized and partially characterized in the purple non-sulfur bacteria R. rubrum [73,74] and Rhodopseudo-monas sphaeroides (recently renamed Rhodobacter sphaeroides) [57]. In situ characterization of the iron-sulfur centers likely to be associated with succinate dehydrogenase has been accomplished for Rps. capsulata [59] and C. vinosum [51]. Of particular interest is the presence of a succinate-reducible [51,57,58,73] and fu-marate-oxidizable [51] iron-sulfur cluster with near +50 mV that, like center S-3 [60,61,75,76] of mitochondrial succinic dehydrogenase (Complex II), is paramagnetic in the oxidized state. The enzyme in phototrophic bacteria also appears to have one or two ferredoxin-like (i.e., paramagnetic in the reduced state) iron-sulfur centers that correspond to centers S-1 (succinate-reducible, EJ ranging from... 

The RCs in photosynthetic organisms have been classified into two groups, i.e., quinone-type and iron sulfur-type. The quinone-type RCs are present in purple non-sulfur bacteria as well as in the PS II of cyanobacteria and chloroplasts (of algae and higher plants), whereas the iron sulfur-type RCs are present in green and purple sulfur bacteria as well as in the PS I of cyanobacteria and chloroplasts (Blankenship, 1992 HauskaetaL, 1995). 

Tryptophan M-250 (Trp °) in the reaction center (RC) of the purple non-sulfur bacteria occupies a key position between the photoactive pheophytin (H ) and the primary quinone Qf), according to the X-ray crystal structures obtained for Rps. viridis and Rb. sphaeroides (refs. 1,2 Fig. 1). 

Bacteriochloro-phyll a Purple sulfur bacteria (Chro-matiaceae, formerly Thiorho-daceae), purple non-sulfur bacteria (Rhodospirillacaeae, formerly Athiorhodaceae). Acetyl on C2 H methyl on C3 H ethyl on C4 (i. e. it is a dihydrochlorophyll) phytol or geranylger-aniol esterified to the C7 propionic acid residue. Both ring II and ring IV are more reduced than in chlorophyll c. A tetrahydroporphyrin... 

Heterotrophic bacteria Iron-oxidizing bacteria Purple non-sulfur bacteria... 

Purple Non-Sulfur Bacteria Photo-Fermentative Hydrogen Production. 376... 

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