Molecular evidence for a close phylogenetic relationship among box-shaped halophilic bacteria, Halobacterium vallismortis, and Halobacterium marismortui

Abstract

The 5S rRNA from H. vallismortis, H. marismortui (the Ginzburg strain) and 2 extremely halophilic isolates that exhibit an unusual box-shaped morphology were examined by RNase T1 fingerprinting. The 5S rRNA are essentially identical, and the 4 strains are in fact close phylogenetic relatives that should properly be assigned to a single genus. Comparison with previously available 5S rRNA sequence data from H. cutirubrum and Halococcus morrhuae indicates that the 4 strains examined are quite distinct from both. It is further argued that this molecular evidence is not inconsistent with the previously proposed creation of a new genus, Haloarcula.