Rhodopseudomonas rutila, a New Species of Nonsulfur Purple Photosynthetic Bacteria

Abstract

Strains R1T (type strain) and R2, 2 new isolates of nonsulfur purple photosynthetic bacteria, were studied. The cells of these organisms were gram-ngative nonsporeforming rods that were motile by means of a single flagellum and they multiplied by budding. The photosynthetic systems of these strains were of the lamellar type parallel to the cytoplasmic membrane. Cells which formed under anaerobic conditions in the light were red. The cells of these strains contained bacteriochlorophyll a, ubiquinone 10 and carotenoids. No vitamins were required as growth factors and reduced S compounds could not be utilized by strains R1T and R2. These 2 strains produced H2 anaerobically in the light. On the basis of this study, a new species, R. rutila, is proposed for strains R1T and R2. The guanine-plus-cytosine contents of the DNA of strains R1T and R2 are 67.6 and 69.4 mol%, respectively. The type strain of this new species is strain R1 (= ATCC 33872).