The bchP gene product of Rhodobacter sphaeroides is responsible for the reduction of the isoprenoid moiety of bacteriochlorophyll (Bchl) from geranylgeraniol (GG) to phytol; here, we show that this enzyme also catalyzes the reduction of the isoprenoid moiety of bacteriopheophytin (Bphe). In contrast, we demonstrate that a newly identified homolog of this gene in Rhodospirillum rubrum encodes an...

Carotenoid production was determined in illuminated anaerobically maintained cultures of Rhodospirillum rubrum in media with and without 4-[beta-(diethylamino)-ethoxy]-benzophenone. In treated cultures, lycopene--which normally is not produced by R. rubrum--accumulated as the predominant pigment, and total carotenoids increased five- to sixfold.

Holt, Stanley C. (University of California, Davis), and Allen G. Marr. Location of chlorophyll in Rhodospirillum rubrum. J. Bacteriol. 89:1402-1412. 1965.-If cells of Rhodospirillum rubrum are broken by sonic and ballistic disruption, the chlorophyll is not found in discrete cytoplasmic structures, but is located in a more extensive structure of the cell, the intracytoplasmic membrane. Direct e...

The lamellae of the bacterium Rhodospirillum molischianum originate as extensions of the cytoplasmic membrane into the cytoplasm of the cell. Initially, these extensions are narrow folds and occur independently of one another. The first lamellae to appear average about 80 A in width, representing one side of the infolded cytoplasmic membrane, or 160 A when the two sides of the fold are closely ...

Large single crystals of the high potential iron-sulfur protein isolated from Rhodospirillum tenue strain 3761 have been obtained. They belong to the space group P2(1) with unit cell dimensions of a = 36.7 A, b = 52.6 A, c = 27.6 A, and beta = 90.8 degrees. There are two molecules in the asymmetric unit. Based on oscillation photographs, the crystals diffract to at least 1.6 A resolution. They ...

The genus Rhodospirillum is represented by four species, with three of them showing phylogenetic divergence compared to the type species, Rhodospirillum rubrum. Differences in the major diagnostic properties such as internal photosynthetic membranes, quinones, fatty acids, carotenoid composition and a few other phenotypic properties warrant the reclassification of members of this genus. Resulta...

Holt, Stanley C. (University of California, Davis), and Allen G. Marr. Isolation and purification of the intracytoplasmic membranes of Rhodospirillum rubrum. J. Bacteriol. 89:1413-1420. 1965.-When Rhodospirillum rubrum was disrupted in a French pressure cell, two colored bands were observed after density-gradient centrifugation: an upper band containing chromatophores and a lower band containin...

Holt, Stanley C. (University of California, Davis), and Allen G. Marr. Effect of light intensity on the formation of intracytoplasmic membrane in Rhodospirillum rubrum. J. Bacteriol. 89:1421-1429. 1965.-Cells of Rhodospirillum rubrum grown at low light intensity were found to contain much more internal membrane than cells grown at high light intensity. Highly purified membranes (chromatophores)...

The mechanism of conversion of substrate hydrogen to H2 in microbial fermentations is still obscure. One of the enzymes presumably involved in the final phase of H2 formation is hydrogenase, which catalyzes the reaction H2 =2H+ + 2e (Stephenson and Stickland, 1931). The present investigation was stimulated by our interest in the presumed participation of hydrogenase in photochemical production ...