Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CHROMATIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMedDate not supplied

[Molecular organization of the long-wave complexes of purple photosynthesizing bacteria. Effect of pronase on the B890 complex of Chromatium minutissium and Rhodopseudomonas palustris].

The pronase action on the long-wave complexes B890 from two different purple bacteria has been investigated. Differences in the kinetics of decrease of the reaction center photochemical activity of electron-donor activity of cytochromes and of destruction of Bx890 (875) forms have been discovered. Different rates of the proteolysis of RC proteins were revealed by SDS-gel-electrophoresis. The heavy protein of RC was the first to degrade. The photochemical transformations deltaA890(875) in B890 complexes was observed during formation of peptides with molecular weight about 17 000 from two other RC proteins. On the basis of obtained data the model of molecular organization of B890 complexes from purple bacteria is discussed.

Bacterial Chromatophores↗
PubMedDate not supplied

[Possibility of using light of different wavelengths for growing Chromatium vinosum in heterotrophic conditions].

The photoautotrophic purple sulphur bacterium Chronatium vinosum was found to be capable of heterotrophic growth under anaerobic conditions at the expense of light energy. No growth was detected under anaerobic conditions in the absence of light. The energy of monochromatic red light (715, 726, 739, 776, 815 nm) and green light (534 and 535 nm), as well as of green luminescent light (a broad maximum at 500-560 nm, a peak at 520 nm) and white light, was used by the bacterium for the growth under anaerobic conditions in the presence of acetic acid as a sole source of carbon. The rate of biosynthesis of the cellular matter, proteins and pigments (bacteriochlorophyll and carotenoids) was different depending on the spectrum: light having wavelengths of 534, 535 and 715 nm was favourable, and infrared light having a wavelength of 815 nm was most effective. The heterotrophic growth of the bacterium depended also on the intensity of light, the optimum energy being 14-10(3)-20-10(3) erg/cm2/sec.

Acetates↗
PubMed1998

Phylogenetic relationships among the Chromatiaceae, their taxonomic reclassification and description of the new genera Allochromatium, Halochromatium, Isochromatium, Marichromatium, Thiococcus, Thiohalocapsa and Thermochromatium.

Sequences of the 16S rDNA from all available type strains of Chromatium species have been determined and were compared to those of other Chromatiaceae, a few selected Ectothiorhodospiraceae and Escherichia coli. The clear separation of Ectothiorhodospiraceae and Chromatiaceae is confirmed. Most significantly the sequence comparison revealed a genetic divergence between Chromatium species originated from freshwater sources and those of truly marine and halophilic nature. Major phylogenetic branches of the Chromatiaceae contain (i) marine and halophilic species, (ii) freshwater Chromatium species together with Thiocystis species and (iii) species of the genera Thiocapsa and Amoebobacter as recently reclassified [Guyoneaud, R. & 6 other authors (1988). Int J Syst Bacteriol 48, 957-964], namely Thiocapsa roseopersicina, Thiocapsa pendens (formerly Amoebobacter pendens), Thiocapsa rosea (formerly Amoebobacter roseus), Amoebobacter purpureus and Thiolamprovum pedioforme (formerly Amoebobacter pedioformis). The genetic relationships between the species and groups are not in congruence with the current classification of the Chromatiaceae and a reclassification is proposed on the basis of 16S rDNA sequence similarity supported by selected phenotypic properties. The proposed changes include the transfers of Chromatium minus and Chromatium violascens to Thiocystis minor comb. nov. and Thiocystis violascens comb. nov., of Chromatium vinosum, Chromatium minutissimum and Chromatium warmingii to the new genus Allochromatium as Allochromatium vinosum comb. nov., Allochromatium minutissimum comb. nov., and Allochromatium warmingii comb. nov., of Chromatium tepidum to the new genus Thermochromatium as Thermochromatium tepidum comb. nov., of Chromatium salexigens and Chromatium glycolicum to the new genus Halochromatium as Halochromatium salexigens comb. nov. and Halochromatium glycolicum comb. nov., of Chromatium gracile and Chromatium purpuratum to the new genus as Marichromatium gracile comb. nov. and Marichromatium purpuratum comb. nov., of Thiocapsa pfennigii to Thiococcus pfennigii gen. nom. rev., of Thiocapsa halophila to the new genus Thiohalocapsa as Thiohalocapsa halophila comb. nov., and of Chromatium buderi to the new genus Isochromatium as Isochromatium buderi comb. nov.

Chromatiaceae↗
PubMed1975

Cytochrome b and photosynthetic sulfur bacteria.

Chromatophores isolated from the purple sulfur bacterium Chromatium and the green sulfur bacterium Chlorobium exhibit absorbance changes in the cytochrome alpha-band region consistent with the presence of a b-type cytochrome. Cytochrome content determined by reduced minus oxidized difference spectra and by heme photochemically active bacteriochlorophyll (reaction-center bacteriochlorophyll). The b-type cytochrome in Chromatium has an alpha-band maximum at 560 nm and a midpoint oxidation-reduction potential of -5 mV at pH 8.0. The b-type cytochrome in Chlorobium has an alpha-band maximum at 564 nm and an apparent midpoint oxidation-reduction potential near -90 mV. Chromatophores isolated from both Chromatium and Chlorobium cells catalyze a photoreduction of cytochrome b that is enhanced in the presence of antimycin A. Antimycin A and 2-n-heptyl-4-hydroxyquinoline-N-oxide inhibit endogenous (but not phenazine methosulfate-mediated) cyclic photophosphorylation in Chromatium chromatophores and non-cyclic electron flow from Na-2S to NADP in Chlorobium chromatophores. These observations suggest that b-type cytochromes may function in electron transport reactions in photosynthetic sulfur bacteria.

Antimycin A↗