Aeropyrum pernix K1^T is an aerobic hyper-thermophilic archaeon and was isolated by a research team (Y. Sako et al) of Kyoto University in 1993 in a hydrothermal vent at Kodakara Island in Kagoshima Prefecture. Partly because it is an aerobic archaeon, its genome was analyzed to compare with the anaerobic P. horikoshii OT3^T(= NBRC 100139^T) genome. The archaeon optimally grows at temperatures between 90 to 95 °C and at pH 7.0 and a salinity of 3.5% with a doubling time of about 200 min. Its growth temperature is somewhat lower than that of P. horikoshii OT3^T. Nonetheless it is still the highest among aerobic hyper-thermophilic archaea whose genomes have so far been analyzed. The archaeon does not require sulfur-containing compounds for growth, and hence does not generate H₂S during growth.

A. pernix K1^T is spherical in shape with 0.8 to 1.0 µm in diameter. Similar to P. horikoshii OT3^T, the genome of this archaeon contains 14 tRNA genes with introns and as much as 50 % of organism-specific genes. It is interesting to note that it possesses and expresses genes encoding 'proliferating cell nuclear antigens' that play roles in the control of cell cycle, DNA-repair and apoptosis in eukaryotic organisms. These gene products were found to enhance processivity of DNA polymerases in A. pernix K1^T cells. Extensive comparative analysis between P. horikoshii OT3^T and A. pernix K1^T and with others would reveal more interesting features associated with their genomes.