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At least 19 recordsLinked to original sources
PubMed1981

Dna-Dna hybridization of Rhodopseudomonas capsulata, Rhodopseudomonas sphaeroides and Rhodopseudomonas sulfidophila strains.

The genetic relatedness of 21 Rhodopseudomonas strains has been studied by means of DNA-DNA hybridization. All strains included in the study belonged to the subgroup of the genus Rhodopseudomonas which is characterized by a short-rod to coccus morphology, a vesicular intracytoplasmic membrane system and carotenoids of the spheroidene group. Mol percentages guanine + cytosine ranged from 64 to 73, most strains having values between 68 and 72. With few exceptions, the hybridization data obtained were in agreement with the subdivision in three (or possibly four) species on the basis of classical taxonomy. Strain SCJ, formerly considered to be a somewhat atypical R. capsulata strain, is most probably R. sphaeroides strain and two out of seven strains that were received as R. sulfidophila did not fit in this species on the basis of the hybridization data. The results also showed that two undesignated strains that were previously thought to be related to R. capsulata (Hansen et al. 1975) cannot be assigned to this species and may be representatives of another species. The seven strains that required approximately 2.5% NaCl in the medium and that had been designated R. sulfidophila were found to synthesize far higher levels of bacteriochlorophyll during fully aerobic growth in the dark than the purple bacteria studied thus far.

DNA, Bacterial↗
PubMed1975

Identification of a 2, 3-diamino-2, 3-dideoxyhexose in the lipid A component of lipopolysaccharides of Rhodopseudomonas viridis and Rhodopseudomonas palustris.

A hitherto unknown amino sugar (Compound A), detected in acid hydrolyzates of lipopolysaccharides of Rhodopseudomonas viridis and Rhodopseudomonas palustris, is present in the Lipid A component but not in the O-specific part of the lipopolysaccharides. 2-Amino-2-deoxy-D-glucose is lacking in the purified Lipid A of both strains. Compound A, characterized by a very high migration in paper electrophoresis was obtained in a pure state by ion-exchange chromatography and shown by m.s. of the alditol acetate to be a 2, 3-diamino-2, 3-dideoxyhexose. G.l.c. and periodate oxidation excluded all possible stereoisomers with the exception of 2, 3-diamino-2, 3-dideoxyglucose and 2, 3-diamino-2, 3-dideoxydose. G.l.c. of the alditol acetates of Compound A and of the glucose derivative suggests that Compound A is 2, 3-diamino-2, 3-dideoxyglucose. The significance of the occurrence of this new aminodeoxy sugar in the Lipid A component of Rhodopseudomonas viridis and Rhodopseudomonas palustris O-antigens for the biological properties of the respective lipopolysaccharides and for the taxonomy of the Rhodospirillaceae family is discussed.

Chromatography, Gas↗
PubMed1980

Regulatory properties of the ADPglucose pyrophosphorylase from Rhodopseudomonas sphaeroides and from Rhodopseudomonas gelatinosa.

The ADPglucose pyrophosphorylases from Rhodopseudomonas sphaeroides and Rhodopseudomonas gelatinosa are activated by fructose-6-phosphate, pyruvate and fructose-1,6 biophosphate-P2. The effects of the activators are to increase significantly the Vmax of ADPglucose synthesis and to lower the S0.5 values (concentration of substrates giving 50% maximal velocity) for ATP and MgCl2. The R. sphaeroides enzyme is inhibited by Pi while the R. gelatinosa enzyme is inhibited by AMP as well as by Pi. The interaction between inhibitor and activator is complex. At very low concentrations of activator the enzyme is more sensitized to inhibition. However, at higher concentrations of activator there is a decrease in the sensitivity of the enzyme towards inhibition. The findings are discussed with respect to glycogen synthesis in these microorganisms and may be related to findings that indicate that Rhodopseudomonads have the ability to degrade sugars via the Entner-Duodoroff or Embden-Meyerhoff pathways.

Adenosine Diphosphate Glucose↗
PubMed1975

Asymmetry of an energy transducing membrane the location of cytochrome c2 in Rhodopseudomonas spheroides and Rhodopseudomonas capsulata.

Monospecific antibodies have been prepared against cytochrome c2 from Rhodopseudomonas spheroides and Rhodopseudomonas capsulata, and against cytochrome c' from Rps. capsulata. These antibodies precipitated their respective antigens, but did not cross react with a wide range of procaryotic or eucaryotic cytochromes, or with other bacterial proteins. The cytochromes produced during aerobic growth were immunologically indistinguishable from those produced during photosynthetic growth. Cytochrome c2 is located in vivo in the periplasmic space between the cell was and the cell membrane, and when chromatophores are prepared from whole cells the cytochrome becomes trapped inside these vesicles. The implications of these results to energy coupling in the photosynthetic bacteria are discussed.

Animals↗
PubMed1981

Resolved difference spectra of redox centers involved in photosynthetic electron flow in Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides.

1. In Rhodopseudomonas sphaeroides the Qx absorption band of the reaction center bacteriochlorophyll dimer which bleaches on photo-oxidation is both blue-shifted and has an increased extinction coefficient on solubilisation of the chromatophore membrane with lauryldimethylamine-N-oxide. These effects may be attributable in part to the particle flattening effect. 2. The difference spectrum of photo-oxidisable c type cytochrome in the chromatophore was found to have a slightly variable peak position in the alpha-band (lambda max at 551--551.25 nm); this position was always red-shifted in comparison to that of isolated cytochrome c2 (lambda max at 549.5 +/- 0.5 nm). The shift in wavelength maximum was not due to association with the reaction center protein. A possible heterogeneity in the c-type cytochromes of chromatophores is discussed. 3. Flash-induced difference spectra attributed to cytochrome b were resolved at several different redox potentials and in the presence and absence of antimycin. Under most conditions, one major component, cytochrome b50 appeared to be involved. However, in some circumstances, reduction of a component with the spectral characteristics of cytochrome b-90 was observed. 4. Difference spectra attributed to (BChl)2, (Formula: see text), c type cytochrome and cytochrome b50 were resolved in the Soret region for Rhodopseudomonas capsulata. 5. A computer-linked kinetic spectrophotometer for obtaining automatically the difference spectra of components functioning in photosynthetic electron transfer chains is described. The system incorporates a novel method for automatically adjusting and holding the photomultiplier supply voltage.

Bacteriochlorophylls↗
PubMed1973

O-methyl sugars in lipopolysaccharides of Rhodospirillaceae. Identification of 3-O-methyl-D-mannose in Rhodopseudomonas viridis and of 4-O-methyl-D-xylose and 3-O-methyl-6-deoxy-D-talose in Rhodopseudomonas palustris respectively.

1. This paper deals with the identification of three O-methyl sugars in lipopolysaccharides isolated from strains of the Gram-negative photosynthetic family Rhodospirillaceae. In addition to the previously described 3-O-methyl-l-xylose, a second O-methyl sugar was encountered in the lipopolysaccharide of Rhodopseudomonas viridis F, namely 3-O-methyl-d-mannose. The lipopolysaccharides of two strains of Rhodopseudomonas palustris (strain 1e5 and 8/1) contain two O-methylsugars, 4-O-methyl-d-xylose and 3-O-methyl-6-deoxy-d-talose (d-acovenose). 4-O-Methyl-d-xylose, but not 3-O-methyl-6-deoxy-d-talose, could be identified in the lipopolysaccharides of the strains K/1 and 2/2 of the same species. 2. The O-methyl sugars described in this communication were isolated by paper chromatography and identified by g.l.c., paper chromatography, high-voltage electrophoresis and mass spectrometry. Besides the genuine sugars, their alditol acetates and their demethylated (parental) forms were investigated. Optical rotation measurements and, in one case, enzymic reactions were used to establish the optical configuration of the sugars under investigation.

Chromatography, Paper↗
PubMed1986

Structural homology of reaction centers from Rhodopseudomonas sphaeroides and Rhodopseudomonas viridis as determined by x-ray diffraction.

Crystals of the reaction center (RC) from Rhodopseudomonas sphaeroides with the space group P2(1)2(1)2(1), have been studied by x-ray diffraction. The Patterson search (molecular replacement) technique was used to analyze the data, with the structure of the reaction center from Rhodopseudomonas viridis as a model system. A preliminary electron density map of the reaction center from R. sphaeroides has been obtained. Comparison of the structure of the RC from R. sphaeroides with that from R. viridis showed the following conserved features: five membrane-spanning helices in each of the L and M subunits, a single membrane-spanning helix in the H subunit, a 2-fold symmetry axis, and similar positions and orientations of the cofactors. Unlike the RCs from R. viridis, both quinones are retained in the RCs from R. sphaeroides. The secondary quinone is located near the position related by the 2-fold symmetry axis to the primary quinone.

Bacterial Proteins↗
PubMed1997

Transfer of the bacteriochlorophyll b-containing phototrophic bacteria Rhodopseudomonas viridis and Rhodopseudomonas sulfoviridis to the genus Blastochloris gen. nov.

The phylogenetic positions of the bacteriochlorophyll (BChl) b-producing budding phototrophic bacteria Rhodopseudomonas viridis and Rhodopseudomonas sulfoviridis were studied on the basis of 16S rRNA gene sequence information. These bacteria formed a tight cluster with the genus Rhodoplanes as a sister group within the alpha-2 subgroup of the Proteobacteria. Genomic DNA-DNA hybridization assays showed that R. viridis and R. sulfoviridis were closely related but were different species. Creation of the genus Blastochloris gen. nov. is proposed to accommodate these BChl b-producing species of phototrophic bacteria.

DNA, Bacterial↗
PubMed1982

Purification and properties of the coupling-factor ATPases F1 from Rhodopseudomonas palustris and Rhodopseudomonas sphaeroides.

The coupling-factor ATPases from photosynthetically grown Rhodopseudomonas palustris and Rhodopseudomonas sphaeroides were purified by the same procedure to homogeneity. Gel chromatography on Sephacryl S-300 Superfine shortened the process of purification and improved its yield. Solubilization of the ATPase from both bacteria was found to be dependent on a specific sonication treatment of the cell suspensions, indicating a very weakly bound F1-ATPase in R. palustris. Depleted chromatophores could be restored in photophosphorylation and membrane-bound ATPase activities by adding the solubilized ATPase protein. The purified enzymes did not show a markedly trypsin-stimulated or dithiothreitol-stimulated activity. Isoelectric focusing and chromatofocusing revealed isoelectric points of 5.0 for both F1-ATPases. The molecular weights were determined by gel chromatography plus high-performance liquid chromatography. Hence, we calculated a molecular weight of 350000 for both F1-ATPases. Sodium dodecylsulfate/polyacrylamide gel electrophoresis revealed five subunits for both enzymes. Kinetic parameters, regarding substrate specificity, the effect of divalent cations, Km and Ki values for the membrane-bound and solubilized ATPases were determined.

Bacterial Proteins↗
PubMed1988

The hopanoids of the purple non-sulfur bacteria Rhodopseudomonas palustris and Rhodopseudomonas acidophila and the absolute configuration of bacteriohopanetetrol.

Five complex hopanoids have been detected in the purple non-sulfur bacterium Rhodopseudomonas acidophila. Next to the polyfunctionalized methylcyclopentane bacteriohopanetetrol ether already isolated from Methylobacterium organophilum, 35-carbamoylbacteriohopane-32,33,34-triol, 34,35-dicarbamoylbacteriohopane-32,33-diol and two nucleoside analogues, (22R)-30-(5'-adenosyl)hopane and (22S)-30-(5'-adenosyl)hopane were isolated and identified by spectroscopic and chemical methods. In Rhodopseudomonas palustris, however, only 35-amino-bacteriohopane-32,33,34-triol was detected. Chemical correlation between adenosylhopane and bacteriohopanetetrol, as well as comparison of derivatives obtained from bacterial and synthetic hopanoids, permitted the determination of the configurations of all asymmetric centres of the side-chain of bacteriohopanetetrol as 22R, 32R, 33R and 34S. According to the stereochemistry, this side-chain could be a D-ribose derivative linked through its C-5 carbon atom to the hopane skeleton.

Chromatography, Gas↗
PubMed1981

Substrate specificity of citrate lyase deacetylase of Rhodopseudomonas gelatinosa and Rhodopseudomonas palustris.

Citrate lyase (EC 4.1.3.6) isolated from Rhodopseudomonas palustris was investigated with regard to its kinetic properties and its subunit composition. This enzyme was inactivated by citrate lyase deacetylase (EC 3.1.2.-) of Rhodopseudomonas gelatinosa. A corresponding cross-reaction was measured with partially purified deacetylase of R. palustris and citrate lyase of R. gelatinosa. The three different subunit types (alpha, beta, and gamma) of citrate lyase from R. gelatinosa wee purified to homogeneity, and antibodies were prepared against each of the three subunits and against the native enzyme complex. In corresondence with the enzymatic interactions, immunological cross-reactions were found between anti-enzyme and anti-large subunit antibodies and citrate lyase from R. palustris. On the other hand, no immunological cross-reactions were detectable among each of the antibodies and citrate lyases from Enterobacter aerogenes, Streptococcus diacetilactis, and Clostridium sphenoides. Antibodies against the large subunit of citrate lyase inhibited the deacetylase, but antibodies against the middle and small subunits did not, indicating that the large subunits of citrate lyase are involved in binding the deacetylase.

Antibodies, Bacterial↗
PubMedDate not supplied

[Nitrogenase and hydrogenase activities of the non-sulfur purple bacteria, Rhodopseudomonas spheroides and Rhodopseudomonas capsulata].

The greatest rate of acetylene reduction by Rhodopseudomonas spheroides and Rhodopseudomonas capsulata strains was found in the light in the presence of pyruvate, malate or lactate as well as, in the case of Rh. capsulata, in the presence of 10% H2. The activity of nitrogenase was higher in cells grown in the medium with malate than in cells cultivated in the medium with lactate. All the three strains of Rh. spheroides were characterized by a direct correlation between the rates of H2 photoproduction and C2H2 photoreduction. Such a correlation was not found for Rh. capsulata strains. This can be attributed to the fact that Rh. capsulata strains capable of effective H2 uptake utilize hydrogen evolved in the light in the presence of nitrogenase from organic substrates in order to reduce endogenous electron acceptors or acetylene, i.e. its recyclization takes place. In contrast to Rh. capsulata, Rh. spheroides cells exhibit a weaker hydrogenase activity measured in terms of hydrogen evolution and hydrogen uptake. The uptake of H2 is most active at the account of endogenous H-acceptors or in the presence of benzyl viologen and methylene blue but not methyl viologen.

Acetylene↗
PubMed1995

[Isolation and identification of Rhodopseudomonas viridis and Rhodopseudomonas sulfoviridis].

Under selective culture conditions, two pure cultures (strain G and strain SG) of the purple nonsulfur photosynthetic bacteria containing bacteriochlorophyll b were isolated from pulp effluent and sludge of sewage treatment plant by means of agar shake dilution. Although the cells of strain G and strain SG contained bacteriochlorophyll b and carotenoids, intra-cytoplasmic membranes were of lamellar type parallel to cytoplasmic membrane, the two strains differ in using various organic carbon sources, depending on reduced sulfur compounds and assimilate sulfate. According to Bergey's Manual of Systematic Bacteriology Volume 3, strain G was identified to be Rhodopseudomonas viridis,, strain SG was identified to be Rhodopseudomonas sulfoviridis.

China↗
PubMed1987

fbc operon, encoding the Rieske Fe-S protein cytochrome b, and cytochrome c1 apoproteins previously described from Rhodopseudomonas sphaeroides, is from Rhodopseudomonas capsulata.

Detailed comparison of the 'Rhodopseudomonas sphaeroides GA' strain used by Gabellini et al. (1985) with genuine R. sphaeroides and R. capsulata strains indicated that the previously reported fbc operon of R. sphaeroides (Gabellini and Sebald, 1986) encoding the structural genes for the Rieske Fe-S protein, cytochrome b and cytochrome c1 subunits of the ubiquinol:cytochrome c2 oxidoreductase, is not from R. sphaeroides, but is rather from a strain of R. capsulata. Consequently, the genuine bc1 genes from R. sphaeroides were cloned using corresponding R. capsulata genes as probes, and a partial nucleotide sequence for the Rieske Fe-S protein of R. sphaeroides was determined and compared with that of R. capsulata.

Amino Acid Sequence↗
PubMed1976

Rhodopseudomonas sphaeroides forma sp. denitrificans, a denitrifying strain as a subspecies of Rhodopseudomonas sphaeroides.

From polluted water of a lagoon pond a new type of denitrifying photosynthetic purple bacteria was isolated. With respect to morphology, fine structure, photopigments, requirement for growth factors, the range of utilization of organic substrates for phototrophic growth and DNA base ratio, the denitrifying strains show the closest resemblance to Rhodopseudomonas sphaeroides and were therefore described as a subspecies named R. sphaeroides forma sp. denitrificans. The new isolates grow well with nitrate anaerobically in the dark accompanying the evolution of nitrogen gas. They cannot assimilate nitrate as the nitrogen source for growth.

Aerobiosis↗
PubMed1974

Bacteriophages of Rhodopseudomonas spheroides: isolation and characterization of a Rhodopseudomonas spheroides bacteriophage.

A DNA-containing bacteriophage, designated RS1, infecting Rhodopseudomonas spheroides 2.4.1, has been isolated from sewage. The buoyant density of RS1 in CsCl equilibrium centrifugation is 1.50 g/cm(3), and the buoyant density of RS1 DNA is 1.706. The phage possesses a polyhedral head, approximately 65 nm in diameter, and a tail 60 nm long. When grown on aerobic cells, RS1 has a latent period of 120 min and an average burst size of 20. When grown on anaerobic cells, RS1 has a latent period of 150 min, and a burst size similar to that observed during aerobic infection. The adsorption rate constant of RS1 to aerobic cells is 1.2 x 10(-9) ml/min, and 0.58 x 10(-9) ml/min to anaerobic cells. Adsorption of RS1 to R. spheroides requires the presence of divalent cations.

Adsorption↗