Halochromatium roseum sp. nov., a non-motile phototrophic gammaproteobacterium with gas vesicles, and emended description of the genus Halochromatium.

A rod-shaped, marine, phototrophic, purple sulfur bacterium containing gas vesicles was isolated from a marine solar saltern at Kakinada, India. Cells of strain JA134(T) are Gram-negative, non-motile rods, with vesicular intracytoplasmic membranes, and the strain has an absolute requirement for NaCl for growth. Bacteriochlorophyll a and the carotenoid okenone are present as photosynthetic pigments. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA134(T) clusters with members of the genus Halochromatium, but is distinctly separated from the species reported so far. The morphological and physiological differences of strain JA134(T) from other Halochromatium species support the description of strain JA134(T) (=ATCC BAA-1363(T) =DSM 18859(T) =JCM 14151(T)) as the type strain of a novel species, Halochromatium roseum sp. nov.