The chlorophylls of green bacteria

Purification of membrane‐bound cytochromes and a photoactive P840 protein complex of the green sulfur bacterium Chlorobium limicola f. thiosulfatophilum

“…Heme-positive cytochrome c-550.5 is found in both zones, in discrete concentration peaks. The spectra of the brownish zone in fig.2 show that only a small amount of BChl c (or bacteriopheophytin [25]) and about 0.25 cytochrome c-550.5 per cytochrome b-562 are present (assuming E = 20 mM_' *cm-' at the a-peaks). Redox titrations, performed at pH 6.2 as in [26], COOMASSIE HEME kD I 6%…”

Studies on the structure of a pigment related to chlorophyll a produced by Rhodopseudomonas spheroides

“…If compound 2 is 2-devinyl-2-hydroxyethylphaeophorbid a, dehydration of the hydroxylated (Stanier & Smith, 1960) Amax. side chain should yield phaeophorbid a.…”

“…One of the pigments (compound 2 of Jones, 1963 b), which was isolated from the inhibited cells and medium, corresponds very closely in spectroscopic properties with the magnesium-free derivative of Chlorobium chlorophyll (650), the photosynthetic pigment of certain bacteria (Stanier & Smith, 1960). Compound 2 differs from Chlorobium phaeophorbid (650) in that it gives a positive reaction in the Molisch phase test for the presence of an isocyclic ring substituted with a carboxylic group, a reaction given by chlorophyll a, bacteriochlorophyll and the magnesium-free derivatives of these compounds (phaeophytins).…”

Sulfur globule oxidation in green sulfur bacteria is dependent on the dissimilatory sulfite reductase system

“…To remove traces of ascorbate, the pellet was washed with 500 ml Na 2 HPO 4 /NaH 2 PO 4 (20 mM, pH 7.0) and stored at 280 uC until the measurements were performed. Elemental sulfur, BChl c and BChl d were extracted by resuspending the cell pellet in methanol, and the concentrations were determined spectrophotometrically in the supernatant at 265, 669 and 659 nm, respectively, using absorption coefficients of 23.9 l g 21 cm 21 (Stal et al, 1984), 86 l g 21 cm 21 and 82.3 l g 21 cm 21 (Stanier & Smith, 1960). The A 265 was corrected for pigment contribution by subtracting 40 % of the A 669 and A 659 , respectively (this percentage was empirically determined with sulfur globule-free wild-type cells).…”