2010 年 56 巻 4 号 p. 313-319
Strain JA430T is a Gram-negative, vibrioid to spiral shaped phototrophic purple sulfur bacterium isolated from anoxic sediment of a saltern at Kanyakumari in a mineral salts medium that contained 2% NaCl (w/v). Strain JA430T grows optimally at 5−6% NaCl and tolerates up to 12% NaCl. Intracellular photosynthetic membranes were of the lamellar type. Bacteriochlorophyll a and carotenoids of the spirilloxanthin series are present as photosynthetic pigments. Major cellular fatty acids are C18:1ω7c, C16:0, C19:0cycloω8c and C16:1ω7c/C16:1ω6c. Strain JA430T exhibits photoorganoheterotrophy and chemoorganoheterotrophy and requires para-aminobenzoic acid, pantothenate and pyridoxal phosphate for growth. Phylogenetic analysis on the basis of 16S rRNA gene sequence analysis showed that strain JA430T forms monophyletic group in the genus Ectothiorhodospira. The highest sequence similarity for strain JA430T was found with the type strains of Ectothiorhodospira variabilis DSM 21381T (96.1%) and Ectothiorhodospira haloalkaliphila ATCC 51935T (96.2%). Morphological and physiological characteristics discriminate strain JA430T from other species of the genus Ectothiorhodospira, for which we describe this as a novel species, Ectothiorhodospira salini sp. nov. ( = NBRC 105915T = KCTC 5805T).