Rhodoferax Fermentans Research Articles

The high potential iron-sulfur protein (HiPIP) from Rhodoferax fermentans is competent in photosynthetic electron transfer

The functional role of the High Potential Iron-sulfur Protein (HiPIP) from the photosynthetic bacterium Rhodoferax fermentans was investigated. We demonstrated that the HiPIP increased the rate of light-induced oxygen reduction mediated by the photosynthetic reaction center (RC); this stimulation reached half-saturation at [HiPIP]/[RC] ca. 15. The capability of the HiPIP in delivering electrons to the reaction center of Rhodoferax fermentans was demonstrated through kinetic spectrophotometry of cytochrome c-556 oxidation in the presence or in the absence of HiPIP. It is concluded that the HiPIP is competent in the photosynthetic electron transfer chain of Rhodoferax fermentans.

High Potential Iron-Sulfur Protein (HiPIP) is an Efficient Electron Donor to the Photosynthetic Reaction Center of the Purple Phototroph Rhodoferax Fermentans

High Potential Iron-Sulfur Protein (HiPIP) is an Efficient Electron Donor to the Photosynthetic Reaction Center of the Purple Phototroph Rhodoferax Fermentans

Phylogenetic affiliations ofRhodoferax fermentans and related species of phototrophic bacteria as determined by automated 16S rDNA sequencing

16S rDNA sequences of strains of Rhodoferax fermentans were analyzed and compared with those of species of the genera Rubrivivax and Rhodocyclus. Approximately 1.5-kb fragments of 16S rDNA from crude cell lysates were amplified by the polymerase chain reaction (PCR) and sequenced directly by using Tth DNA polymerase with the linear PCR sequencing protocol, followed by on-line detection with an automated laser fluorescent DNA sequencer. Pairwise sequence comparisons and distance matrix tree analysis showed that Rhodoferax fermentans, Rubrivivax gelatinosus, and Rhodocyclus species belong to three separate lineages within the beta subclass of the Proteobacteria, thereby confirming the phylogenetic validity of the genus Rhodoferax, as well as of the genera Rubrivivax and Rhodocyclus.

Rhodoferax fermentans gen. nov., sp. nov., a phototrophic purple nonsulfur bacterium previously referred to as the ?Rhodocyclus gelatinosus-like? group

Strains of the phototrophic bacteria previously referred to as the “rhodocyclus gelatinosus-like (RGL)” group were taxonomically studied in comparison with Rhodocyclus species. Cells of the RGL strains were curved rods and motile by means of polar flagella. They contained bacteriochlorophyll a and carotenoids of the spheroidene series. The intracytoplasmic membrane system was absent. Photoorganotropho with various organic compounds as carbon sources was the preferred mode of growth. Aerobic growth at full atmospheric oxygen tension and fermentative growth under anaerobic-dark conditions were also possible. The major cellular fatty acids were palmitoleic acid and palmitic acid, and 3-hydroxylated fatty acids with octanoic acid predominating were also found. Both ubiquinone-8 and rhodoquinone-8 occurred as major quinones. The mol% guanine plus cytosine of the DNAs varied between 59.8 and 60.3. DNA-DNA hybridization studies showed that the RGL strains were highly related to each other but exhibited low levels of the homology to Rhodocyclus species. These data allow the establishment of the RGL group as a new taxon of the purple nonsulfur bacteria, for which the name Rhodoferax fermentans gen. nov., sp. nov. is proposed.