Coccoid cells very irregular, 0.8-1 microns in diameter. Cell envelope type S of 25 nm in thickness. Gram negative. Highly mobile, presence of pili. Strictly aerobic, heterotrophic hyperthermoneutrophiles. Optimal growth conditions: 90-95 ° C (70-100 ° C), pH 7 (5-9) and NaCl 35 g / l (18-70 g / l). Use of complex protein compounds. DNA: 56 mol% G+ C. A single species, Aeropyrum pernix .
