Aeropyrum pernix is a solely aerobic organism growing above 95°C under atmosphere. This marine hyperthermophilic archaeon is a member of the phylum Crenarchaeota, deeply branching within the universal phylogenetic tree based on 16S rRNA gene. It was isolated from a coastal solfataric vent in Kodakara-Jima Island in southwestern Japan and grows under strictly aerobic conditions heterotrophically on various proteinaceous complex compounds optimally at 90 to 95°C. The other closely related species in the genus, Aeropyrum camini, was isolated from a deep-sea hydrothermal vent at the Suiyo-Seamount in the Izu-Bonin Arc, Japan, at a depth of 1385 m. The cell membrane of A. pernix is mainly composed of unique polar lipids. The complete genome sequence of A. pernix K1 has been determined for the first time in Crenarchaeota. Three introns are surprisingly located within the rRNA operon, two of which harbor homing endonucleases. Two proviral regions were identified in the genome and they were practically induced under suboptimal condition. Another two novel viruses are also isolated from the geothermal environment. Due to its unique phenotypes (aerobic and hyperthermophilic), a lot of enzymes from A. pernix are studied for industrial applications. Extracellular and intracellular proteases, SOD and hydrogenase showed oxygen tolerance and high thermo stability above 100°C, meaning that they can be practically applied as industrial catalysts. Further, a cysteine synthase with an extremely high activity, which catalyzes the formation of L-cysteine, has been applied to produce L-cysteine used as materials for medicines and cosmetics for whitening effects. This archaeon has extreme potential in industry.
Aeropyrum pernix is a species of extremophile archaea in the archaeal phylum Thermoproteota. It is an obligatorily thermophilic species. The first specimens were isolated from sediments in the sea off the coast of Japan.
Aeropyrum pernix was the first strictly aerobic hyperthermophilic Archaea to be discovered. It was originally isolated from heated marine sediments and venting water collected in 1996 from a solfataric vent at Kodakara-jima Island in Kyūshū, Japan.[1]
Its complete genome was sequenced in 1999 and is 1,669 kilobases in size, with 2,694 possible genes detected.[2] All of the genes in the TCA cycle were found except for that of α-ketoglutarate dehydrogenase. In its place, the genes coding for the two subunits of 2-oxoacid:ferredoxin oxidoreductase were identified.
The cells of Aeropyrum pernix are spherical in shape and approximately 1 μm in diameter. The envelope surrounding the cells of Aeropyrum is about 25 nm wide. The organisms grows at temperature between 70 and 100 °C (optimum, 90 to 95 °C), at pH 5 to 9 (optimum, pH 7), and at a salinity of 1.8 to 7% (optimum, 3.5% salinity). The growth of the organisms is not detected at 68 or 102 °C. Below 1.5% salinity, cells lyse by low osmotic shock. The cells of the organisms are sensitive to chloramphenicol and insensitive to ampicillin, vancomycin, and cycloserine. It grows well on proteinaceous substances, with a doubling time under these conditions of about 200 minutes.[1] This species lacks the genes for purine nucleotide biosynthesis and thus relies on environmental sources to meet its purine requirements.[3]
Aeropyrum pernix is a species of extremophile archaea in the archaeal phylum Thermoproteota. It is an obligatorily thermophilic species. The first specimens were isolated from sediments in the sea off the coast of Japan.
