Rhodobacter vinaykumarii sp. nov., a marine phototrophic alphaproteobacterium from tidal waters, and emended description of the genus Rhodobacter

Abstract

A rod-shaped, phototrophic, purple non-sulfur bacterium was isolated in pure culture from seawater collected from the seashore of Visakhapatnam, on the east coast of India, in a medium that contained 2 % NaCl (w/v). Strain JA123T was Gram-negative and non-motile and had a requirement for NaCl. Photo-organoheterotrophic and chemo-organoheterotrophic growth occurred with organic compounds as carbon sources and electron donors. Photolithoautotrophic, chemolithoautotrophic and fermentative growth could not be demonstrated. Strain JA123T contained vesicular intracellular photosynthetic membrane structures. Bacteriochlorophyll a and probably carotenoids of the spheroidene series were present as photosynthetic pigments. Biotin was required for growth. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA123T clustered with species of the genus Rhodobacter. Based on 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA123T is sufficiently different from other Rhodobacter species to propose a novel species, Rhodobacter vinaykumarii sp. nov., to accommodate this strain; the type strain is JA123T (=DSM 18714T =JCM 14544T =CCUG 54311T).