[Rhodobaculum claviforme gen. nov., sp. nov., a New Alkaliphilic Nonsulfur Purple Bacterium].
Two alkaliphilic strains of nonsulfur purple bacteria (NPB), B7-4 and B8-2, were isolated from southeast Siberia moderately saline alkaline steppe lakes with pH values above 9.0. The isolates were motile, polymorphous cells (from short rods to long spindly cells) 2.0-3.2 x 9.6-20.0 μm. Intracellular membranes of vesicular type were mostly located at the cell periphery. The microorganisms contained bacteriochlorophyll a and carotenoids of the spheroidene and spirilloxanthin series. The photosynthetic apparatus was represented by LH2 and LH1 light-harvesting complexes. In the presence of organic compounds, the strains grew aerobically in the dark or anaerobically in the light. Capacity for photo- and chemoautotrophic growth was not detected. The cbbl gene encoding RuBisCO was not revealed. Optimal growth of both strains occurred at 2% NaCl (range from 0.5 to 4%), pH 8.0-8.8 (range from 7.5 to 9.7), and 25-35 degrees C. The DNA G+C content was 67.6-69.8 mol %. Pairwise comparison of the nucleotides of the 16S rRNA genes revealed that strains B7-4 and B8-2 belonged to the same species (99.9% homology) and were most closely related to the aerobic alkaliphilic bacteriochlorophyll a-containing anoxygenic phototrophic bacterium (APB) Roseibacula alcaliphilum De (95.2%) and to NPB strains Rhodobaca barguzinensis VKM B-2406(T) (94.2%) and Rbc. bogoriensis LBB1(T) (93.9%). The isolates were closely related to the NPB Rhodobacter veldkampii DSM 11550(T) (94.8%) and to aerobic bacteriochlorophyll a-containing bacteria Roseinatronobacter monicus ROS 35(T) and Roseicitreum antarcticul ZS2-28(T) (93.5 and 93.9%, respectively). New strains were described as a new NPB genus and species of the family Rhodobacteriaceae, Rhodobaculum claviforme gen. nov., sp. nov., with B7-4(T) (VKM B-2708, LMG 28126) as the type strain.
I A
IA
Bryantseva
V A
VA
Gaisin
V M
VM
Gorlenko
D000332:Aerobiosis; D000693:Anaerobiosis; D025541:Bacteriochlorophyll A / Q000378:metabolism; D001482:Base Composition; D002338:Carotenoids / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry*; D020459:Genes, rRNA; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000648:ultrastructure; D060106:Lakes / Q000382:microbiology; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D041902:Rhodobacteraceae / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D012244:Rhodospirillaceae / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D055049:Salt Tolerance; D012800:Siberia; D014871:Water Microbiology; D024341:Xanthophylls / Q000378:metabolism
D025541:Bacteriochlorophyll A; D004269:DNA, Bacterial; D045342:Light-Harvesting Protein Complexes; D012336:RNA, Ribosomal, 16S; D024341:Xanthophylls; C005637:spheroidene; D002338:Carotenoids; C055255:spirilloxanthin