Prosthecochloris indica sp. nov., a novel green sulfur bacterium from a marine aquaculture pond, Kakinada, India

摘要

A green sulfur bacterium, strain JAGS6~T was isolated from a marine aquaculture pond located near Kakinada on the east coast of India. Cells of strain JAGS6~T were Gram-negative, non-motile, coccoid, 1-1.2 μm in diameter, with prosthecae. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JAGS6~T clusters with members of the genus Prosthecochloris and the sequence similarity with the nearest relative, Prosthecochloris vibrioformis, is 96.7%. Cultures of strain JAGS6~T are green in color and the cells contain bacteriochlorophyll c and most likely carotenoids of the chlorobactene series as photosynthetic pigments. Strain JAGS6~T is mesophilic, halotolerant (up to 7% NaCl) and is obligately phototrophic, utilizing sulfide but not thiosulfate as a photosynthetic electron donor. Sulfur globules are deposited outside the cells during oxidation of sulfide. On the basis of 16S rRNA gene sequence analysis and its morphological and physiological characteristics, strain JAGS6~T is distinct from described species of the genus Prosthecochloris and we propose to describe it as a new species, Prosthecochloris indica, sp. nov. The type strain is JAGS6~T (= JCM 13299~T = ATCC BAA1214~T).