Transfer of the bacteriochlorophyll b-containing phototrophic bacteria Rhodopseudomonas viridis and Rhodopseudomonas sulfoviridis to the genus Blastochloris gen. nov.

The phylogenetic positions of the bacteriochlorophyll (BChl) b-producing budding phototrophic bacteria Rhodopseudomonas viridis and Rhodopseudomonas sulfoviridis were studied on the basis of 16S rRNA gene sequence information. These bacteria formed a tight cluster with the genus Rhodoplanes as a sister group within the alpha-2 subgroup of the Proteobacteria. Genomic DNA-DNA hybridization assays showed that R. viridis and R. sulfoviridis were closely related but were different species. Creation of the genus Blastochloris gen. nov. is proposed to accommodate these BChl b-producing species of phototrophic bacteria.