Rhodobacter viridis sp. nov., a phototrophic bacterium isolated from mud of a stream

Abstract

A green phototrophic bacterium (strain JA737T), which was oval-to rod-shaped, Gram-negative and motile, was isolated from mud of a stream in the Western Ghats of India. Strain JA737T contained bacteriochlorophyll a, and the major carotenoid was neurosporene. The major quinone was Q-10 and the polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid, two unidentified phospholipids and five unidentified lipids. Phylogenetic analysis showed that the strain clustered with members of the genus Rhodobacter belonging to the family Rhodobacteraceae of the class Alphaproteobacteria. Based on 16S rRNA gene sequence analysis, strain JA737T had highest sequence similarity with Rhodobacter capsulatus ATCC 11166T (98.8%), Rhodobacter maris JA276T (97%), Rhodobacter aestuarii JA296T (96.7%) and other members of the genus Rhodobacter ( < 96%). However, strain JA737T showed 22-55% DNA-DNA relatedness with the above type strains. On the basis of phenotypic, chemotaxonomic and molecular genetic evidence, strain JA737T represents a novel species of the genus Rhodobacter, for which the name Rhodobacter viridis sp. nov. is proposed. The type strain is JA737T (5KCTC 15167T5MTCC 11105T5NBRC 108864T). © 2013 IUMS.