Aeropyrum pernix
Encyclopedia
Aeropyrum pernix is an extremophile
species of Archaea
that is part of the phylum Crenarchaeota
. It is a heat-requiring species and was isolated from sediment
s in the sea off the coast of Japan
.
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
.
was sequenced in 1999 and is 1,669 kilobases in size, with 2,694 possible gene
s detected. 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.
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 protein
aceous substances, with a doubling time
under these conditions of about 200 minutes.
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...
species of Archaea
Archaea
The Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...
that is part of the phylum Crenarchaeota
Crenarchaeota
In taxonomy, the Crenarchaeota has been classified as either a phylum of the Archaea kingdom or a kingdom of its own...
. It is a heat-requiring species and was isolated from sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s in the sea off the coast of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
Discovery
Aeropyrum pernix was the first strictly aerobicAerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
hyperthermophilic Archaea
Archaea
The Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...
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
Kyushu
is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
Genome structure
Its complete genomeGenome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
was sequenced in 1999 and is 1,669 kilobases in size, with 2,694 possible gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s detected. 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.
Properties
The cells of Aeropyrum pernix are spherical in shape and approximately 1 µmMicrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is 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
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
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 protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
aceous substances, with a doubling time
Doubling time
The doubling time is the period of time required for a quantity to double in size or value. It is applied to population growth, inflation, resource extraction, consumption of goods, compound interest, the volume of malignant tumours, and many other things which tend to grow over time...
under these conditions of about 200 minutes.