show Abstracthide AbstractT. takaii is a deeply branching thermophilic bacteria, but SSU rRNA gene phylogenetic analysis was not sufficient to determine its phylogenetic relationship to other deeply branching bacterial phyla such as Aquificales and Thermodesulfobacteria. In order to clarify the early evolution of the bacterial phyla, the genome project was started. In addition, genome information about its chemolithoautotrophy will also contribute environmental microbial ecology in hydrothermal environments