Allochromatium phaeobacterium sp. nov

Abstract

A rod-shaped, phototrophic, purple sulfur bacterium was isolated in pure culture from brackish water near Bheemli, Visakhapatnam, India, in a medium that contained 2% NaCl (w/v). Strain JA144T was Gram-negative and motile. It did not require salt, but tolerated up to 3% NaCl (w/v). Intracellular photosynthetic membranes were of the vesicular type. Bacteriochlorophyll a and carotenoids that probably belonged to the rhodopinal series were present as photosynthetic pigments. Strain JA144T was able to grow photolithoautotrophically, photolithoheterotrophically and photoorganoheterotrophically. It did not require vitamins. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA144T clustered with species of the genus Allochromatium belonging to the class Gammaproteobacteria. Highest sequence similarities of strain JA144T were found with the type strains of Allochromatium vinosum (96.7% similarity), Allochromatium renukae (96.3 %), Allochromatium minutissimum (95.6 %) and Allochromatium warmingii (89.2 %). Based on 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA144T is sufficiently different from other Allochromatium species to represent a novel species, Allochromatium phaeobacterium sp. nov.; the type strain is JA144T (=JCM 14796T=DSM 19781T). © 2009 IUMS.