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An ovoid to rod-shaped, phototrophic, purple non-sulfur bacterium was isolated from a brown-coloured microbial mat from the brackish water of Bhitarkanika mangrove forest, Dangmal, Orissa, India. Cells of strain JA296(T) were Gram-negative and motile, forming chains of four to eight cells. The colour of the cell suspension grown under anaerobic conditions in the light was yellowish green. Bacteriochlorophyll a and the carotenoids spheroidene and spheroidenone of the spirilloxanthin series were present as photosynthetic pigments. The bacterium was a facultative anaerobe and was able to grow photo-organoheterotrophically and chemo-organoheterotrophically. Thiamine was required as a growth factor. C(18 : 1)omega7c was the dominant fatty acid. Internal cytoplasmic membranes were of the vesicular type. Strain JA296(T) did not require NaCl for growth. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA296(T) was most closely related to Rhodobacter capsulatus ATCC 11166(T) (95.5 % sequence similarity) and clustered with species of the genus Rhodobacter of the family Rhodobacteraceae, class Alphaproteobacteria. On the basis of 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA296(T) represents a novel species of the genus Rhodobacter, for which the name Rhodobacter aestuarii sp. nov. is proposed; the type strain is JA296(T) (=JCM 14887(T) =CCUG 55130(T)).

Two strains of phototrophic, purple non-sulfur bacteria capable of growing at low temperatures (5 degrees C) were isolated from the Himalayas. The two strains showed positive phototaxis and grew over a relatively wide temperature range (5-40 degrees C). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JA194T clustered with members of the genus Rhodobacter. Strain JA194T showed highest 16S rRNA gene sequence similarity with Rhodobacter sphaeroides DSM 158T (99 %). However, DNA-DNA hybridization experiments between Rba. sphaeroides DSM 158T and strain JA194T revealed a level of relatedness of only 67 %. The DNA base composition of strain JA194T was 66.67 mol% G+C (by HPLC). Based on 16S rRNA gene sequence analysis, morphological, physiological, Fourier transform infrared fingerprinting and DNA-DNA hybridization studies, strain JA194T (=KCTC 5602T =JCM 14598T) is sufficiently different from other Rhodobacter species to merit its description as the type strain of a novel species, for which the name Rhodobacter megalophilus sp. nov. is proposed.

During investigations into the diversity of anoxygenic phototrophic bacteria in marine habitats, an ovoid to rod-shaped purple non-sulfur bacterium, designated strain JA276(T), was isolated from enrichments under photoheterotrophic conditions from a marine sediment sampled from the seashore of Cochin, India. Strain JA276(T) is a Gram-negative, motile, chain-forming bacterium that shows optimum growth under photoheterotrophic conditions and is also able to grow chemoorganotrophically. Thiamine is required as a growth factor. Strain JA276(T) contains vesicular intracytoplasmic membranes, bacteriochlorophyll a and the carotenoids spheroidene and spheroidenone. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JA276(T) belongs to the genus Rhodobacter and is closely related to the type strain of Rhodobacter capsulatus (96.2 % sequence similarity). On the basis of the results of 16S rRNA gene sequence analysis and morphological and physiological data, strain JA276(T) is significantly different from other species of the genus Rhodobacter and represents a novel species of the genus, for which the name Rhodobacter maris sp. nov. is proposed. The type strain is JA276(T) (=JCM 14794(T) =ATCC BAA-1549(T) =CCUG 55129(T)).

A novel ovoid, phototrophic, purple non-sulfur bacterium was isolated in pure culture from a sample of sediment from an industrially polluted pond (Noor Mohammad Kunta) in Hyderabad, India. Strain JA234(T) was found to be Gram-negative and non-motile and grew photoheterotrophically with a number of organic compounds serving as carbon source/electron donor. Photo-organoheterotrophic and chemo-organoheterotrophic growth were demonstrated. Biotin and thiamine were required for growth of strain JA234(T). Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA234(T) is most closely related to Rhodobacter azotoformans (97.3 % sequence similarity) and clusters with other species of the genus Rhodobacter of the family Rhodobacteraceae. However, DNA-DNA hybridization with Rba. azotoformans JCM 9340(T) showed a relatedness of only 31.3 % with respect to strain JA234(T). On the basis of 16S rRNA gene sequence analysis, DNA-DNA hybridization data and morphological and physiological characteristics, strain JA234(T) represents a novel species of the genus Rhodobacter, for which the name Rhodobacter ovatus sp. nov. is proposed. The type strain is JA234(T) (=JCM 14779(T)=CCUG 55049(T)).