Halotolerant thermus strains from marine and terrestrial hot springs belong to thermus thermophilus (ex Oshima and Imahori, 1974) nom. rev. emend.

The species “Thermus thermophilus” was validly described by Oshima and Imahori (1974), but was not included in the Approved Lists of Bacterial Names (Skerman et al., 1980) nor in subsequent validation lists. DNA: DNA hybridization studies show that several strains from marine hot springs in the Azores and Fiji, and strains (HB-8, AT-62, GK-24, B, and RQ-1) from terrestrial hot springs are closely related. Moreover, all the strains examined can be distinguished from other species or genomic species of the genus Thermus on the basis of growth at 80 to 82°C and in medium containing 3.0% NaCl. On the basis of these results we propose that Thermus thermophilus (ex Oshima and Imahori, 1974) nom. rev. emend, is a valid species and designate strain HB-8 (ATCC 27634) as the type strain.