Rhodobacter maris sp. nov., a phototrophic alphaproteobacterium isolated from a marine habitat of India

Abstract

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)).