PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Ectothiorhodospira”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

9 recordsLinked to original sources
PubMedDate not supplied

[Growth of Ectothiorhodospira shaposhnikovii on media with various sulfur compounds].

Ectothiorhodospira shaposhnikovii, strain 1, can use thiosulphate, sulphide, sulphite, sulphate, cystein, methionine and glutathione as a source of sulphur during its growth in the light and in the dark. Thiosulphate, sulphide and sulphite are used by the bacterium also as electron donors in photosynthesis so that it can grow in anaerobic autotrophic conditions. Growth of the cultures in the presence of various sulphur compounds depends on the concentration of sodium and potassium salts in the medium, particularly when the bacteria grow in the light and in the dark under aerobic conditions in the presence of such sulphur sources as sulphate, cysteine or methionine. The cells of E. shaposhnikovii produce thiosulphate reductase independent of a source of sulphur and growth conditions. The activity of sulphite reductase can be detected when the cells are cultivated in the presence of sulphates. The activity of APS-reductase has not been found in the cells grown under different conditions.

Aerobiosis↗
PubMed2026

New purple sulfur bacteria genomes from Nebraska salt marsh enrichments.

Two genomes from a Winogradsky column enrichment from the Nebraska salt marshes were sequenced. The analysis of whole-genome phylogeny and average nucleotide identity comparisons indicated that these belong to species of purple sulfur bacteria, Halochromatium and Ectothiorhodospira marina, that have not been described before.

Ectothiorhodospira↗
PubMed1977

Utilization of nitrogen compounds and ammonia assimilation by Chromatiaceae.

Chromatium vinosum strain D, Thiocapsa roseopersicina strain 6311 and Ectothiorhodospira mobilis strain 8112 were grown anaerobically in the light with various single nitrogen sources. When substituted for NH4Cl only glutamine and casamino acids supported good growth of all strains tested. Peptone and urea were utilized by C. vinosum and T. roseopersicina, glutamate, asparagine and nitrate only by C. vinosum. The strains were able to grow with molecular nitrogen; complete inhibition of this growth was observed in the presence of alanine with E. mobilis, and of alanine or asparagine with T. roseopersicina. Glutamate dehydrogenase, requiring either NADH or NADPH, NADH-linked glutamate synthase, and glutamine synthetase were demonstrated in the above organisms grown on NH4Cl.

Amino Acids↗
PubMed1979

Short-lived delayed luminescence of photosynthetic organisms. I. Nanosecond afterglows in purple bacteria at low redox potentials.

A combined study of emissions of purple bacteria Rhodospirillum rubrum, Ectothiorhodospira shaposhnikovii and Thiocapsa roseopersicina was performed under conditions of low potential. It has been shown that a considerable part of the emission represents a delayed luminescence with a lifetime of about 5 ns and an activation energy delta E = 0.05 +/- 0.03 eV. Intensity of this delayed luminescence is approximately equal to that of prompt fluorescence. It diminishes as temperature decreases and also as the intermediate acceptor I becomes reduced after prolonged illumination under low potential conditions. This luminescence represents a radiative decay of the intermediate state, PF, and the luminescence activation energy, delta E, reflects the energy barrier between P*-890 and PF. The value of this barrier determined in the present work is much lower than those obtained previously [3,4,26] for the free-energy release during the primary act of charge separation, basing on redox potential techniques. The reason for this discrepancy is discussed. Delayed luminescence in the picosecond time range is predicted to exist under conditions of active photosynthesis as a result of a small (approx. 0.05 eV) energy barrier between PF and the excited singlet state of reaction center bacteriochlorophyll.

Bacterial Chromatophores↗
PubMedDate not supplied

[Use of urea by purple bacteria].

Strains of purple sulfur bacteria (Chromatium minutissimum, Ectothiorhodospira shaposhnikovii, Thiocapsa roseopersicina, Lamprobacter modestohalophilus) and nonsulfur bacteria (Rhodopseudomonas palustris, Rh. spheroides, Rhodospirillum rubrum) grow in media containing urea as a source of nitrogen at concentrations from 0.5 to 5.0%. They can also utilize the carbon of urea and thus grow in the absence of bicarbonate. Urea is decomposed by all the studied purple bacteria with the participation of urease. In a number of strains, the enzyme is inducible and is synthesized only in the presence of urea. However, it is constitutive in certain purple bacteria (L. modestohalophilus, Rh. palustris, Rh. spheroides). The strains of purple bacteria differ in the activity of urease and in its susceptibility to ammonium ions.

Chromatiaceae↗
PubMedDate not supplied

[Enzymes of carbohydrate metabolism in phototrophic bacteria].

Purple sulphur bacteria (Chromatium minutissimum, Ectothiorhodospira shaposhnikovii, Thiocapsa roseopersicina), non-sulphur bacteria (Rhodopseudomonas palustris Rh. viridis), and green sulphur bacteria (Chlorobium limicola f. thiosulfatophillum) contain all enzymes of the fructose diphosphate pathway of carbohydrate transformation, and also glucose-6-phosphate dehydrogenase. The activity of fructose diphosphate aldolase, triose phosphate dehydrogenase, and glucose-6-phosphate dehydrogenase increased in the cultures of Th. roseopersicina and C. limicola f. thiosulfatophillum when they were grown in the presence of glucose. The activity of 6-phosphogluconate dehydrogenase in these bacteria was very low.

Acetates↗
PubMedDate not supplied

[Possible pathways for acetyl-CoA formation by purple bacteria].

Purple sulfur (Ectothiorhodospira shaposhnikovii, Chromatium minutissimum, Lamprobacter modestohalophilus, Thiocapsa roseopersicina) and nonsulfur (Rhodospirillum rubrum, Rhodopseudomonas palustris, Rhodopseudomonas spheroides) bacteria are capable of forming acetyl-CoA synthetase, phosphotransacetylase and acetokinase independent of the medium composition and growth conditions. In all of the purple sulfur bacteria with an exception of E. shaposhnikovii, the activity of acetokinase is much higher than in purple nonsulfur bacteria. Apart from being involved in the synthesis of acetyl-CoA, such enzymes as phosphotransacetylase, acetokinase and adenylate kinase may play an important role in energy processes of some purple bacteria in the dark.

Acetyl Coenzyme A↗
PubMedDate not supplied

[Carbonic anhydrase activity of phototropic bacteria].

The activity of carboanhydrase was assayed in seven species of phototrophous bacteria: three species of the Rhodospirillaceae genus, three species of the Chromatiaceae genus, and one species of the Chlorobiaceae genus. The activity of carboanhydrase was found in five species among seven. It decreased on passing from photoautotrophous to photoheterotrophous conditions of growth, and then to dark heterotrophous conditions, which correlated with the activity of the Calvin cycle in the bacteria. No activity of carboanhydrase was detected in Ectothiorhodospira shaposhnikovii and Chlorobium limicola, probably because Chl. limicola fixed carbon dioxide not in the Calvin cycle, but in the reactions of reductive carboxylation of organic acids.

Aerobiosis↗