Ectothiorhodospira halochloris

Elemental sulfur was also formed during sulfide oxidation by a cytochrome c-flavocytochrome c-552 complex in Chromatium vinosum (42). Flavocytochromes of different phototrophic bacteria act as sulfide cytochrome c reductases and there was one report that a flavocytochrome possessed even elemental sulfur reductase activity (see 4.9V All flavocytochromes examined so far are heat-labile and are reduced by sulfide forming thiosulfate under strictly anaerobic conditions (4.9V The small acidic cytochromes c-551 of Ectothiorhodospira halochloris and Ectothiorhodospira abdelmalekii. both located on the outside of the cell membrane, stimulated the velocity of sulfide... 

Fig. 2 (A) Structures of bacteriochlorophylls a and b. For BChl a, the substituents Rj and R2 are -H and either phytyl or geranyl-geranyl, respectively. For BChl b, R, is =C-CH, (with omission of the adjacent hydrogen on ring II) and R2 is either phytyl (Rhodopseudomoms viridis) or 2,10-phytadienyl (Ectothiorhodospira halochloris). (B) Structures of bacteriochlorophylls c, d and e. R, is mostly far-nesyl for green sulfur bacteria, mainly stearyl for Chloroflexus auraniiacus. R2-R5 are various substituents each BChl exists as a series of homologs.

Engelhard H, Engel A and Baumeister W. Stoichiometric model of the photosynthetic unit of Ectothiorhodospira halochloris. Proc. Natl. Acad. Sci. USA 1986 83 8972-8976. 

In the search for new substances to protect cells against external environmental effects such as UV radiation, some research has centered on the study of organisms capable of surviving under extreme conditions. These studies show that certain halophilic bacteria, such as Ectothiorhodospira halochloris, contain molecules (ectoins) capable of protecting cells against extreme conditions, maintaining osmotic equilibrium and stabihzing the protein, nucleic acid and biomembrane structures (Beyer, 20(X)). 

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