Complete genome sequence of the thermophilic, hydrogen-oxidizing Bacillus tusciae type strain (T2) and reclassification in the new genus, Kyrpidia gen. nov. as Kyrpidia tusciae comb. nov. and emendation of the family Alicyclobacillaceae da Costa and Rainey, 2010.

Bacillus tusciae Bonjour & Aragno 1994 is a hydrogen-oxidizing, thermoacidophilic spore former that lives as a facultative chemolithoautotroph in solfataras. Although 16S rRNA gene sequencing was well established at the time of the initial description of the organism, 16S sequence data were not available and the strain was placed into the genus Bacillus based on limited chemotaxonomic information. Despite the now obvious misplacement of strain T2 as a member of the genus Bacillus in 16S rRNA-based phylogenetic trees, the misclassification remained uncorrected for many years, which was likely due to the extremely difficult, analysis-hampering cultivation conditions and poor growth rate of the strain. Here we provide a taxonomic re-evaluation of strain T2T (= DSM 2912 = NBRC 15312) and propose its reclassification as the type strain of a new species, Kyrpidia tusciae, and the type species of the new genus Kyrpidia, which is a sister-group of Alicyclobacillus. The family Alicyclobacillaceae da Costa and Rainey, 2010 is emended. The 3,384,766 bp genome with its 3,323 protein-coding and 78 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.