Phylogenetic relationship of phototrophic heliobacteria and systematic reconsideration of species and genus assignments based on genome sequences of eight species.

The draft genome sequences of five species of named phototrophic heliobacteria in the order Clostridiales were determined. Whole genome phylogenetic and average nucleotide identity comparison for the heliobacteria suggests that Heliobacterium chlorum and Heliobacillus mobilis are closely related to one another and belong to the same genus. The three species Heliobacterium modesticaldum, Heliobacterium undosum and Heliobacterium gestii all belong in the same genus, but are more divergent from Hbt. chlorum and belong in a separate genus, which we suggest to be called Heliomicrobium. Heliorestis convoluta is properly recognized to be in the same genus as Heliorestis acidaminivorans. Heliophilum fasciatum is clearly unlike any other and rightfully belongs in a separate genus.

Genome Sequence of the Alphaproteobacterium Blastochloris sulfoviridis DSM 729, Which Requires Reduced Sulfur as a Growth Supplement and Contains Bacteriochlorophyll b.

The genome sequence of Blastochloris sulfoviridis is 3.85 Mb with a GC content of 68%. Its nearest relative is B. tepida (average nucleotide identity [ANI], 91.5%), followed by B. viridis (ANI, 83%). According to ANI and whole-genome-based phylogenetic analysis, the nearest relatives of Blastochloris are Rhodoplanes and Rhodopseudomonas, confirming the recognition of distinct genera.

Genome Sequence of the Acidophilic Nonsulfur Purple Photosynthetic Alphaproteobacterium Rhodovastum atsumiense, a Divergent Member of the Acetobacteraceae Family.

The genome sequence of the acidophile Rhodovastum atsumiense was determined for comparison with that of Rhodopila globiformis Both genomes are unusually large for purple bacteria (7.10 Mb and 7.25 Mb, respectively), and they have an average nucleotide identity of 72%. This value is remarkably similar to the average nucleotide identity values for Acidisphaera, Elioraea, and Paracraurococcus, all aerobic anoxygenic phototrophs.