''Methylacidiphilum infernorum '' is an extremely

acidophilic Acidophiles or acidophilic organisms are those that thrive under highly acidic conditions (usually at pH 5.0 or below). These organisms can be found in different branches of the tree of life, including Archaea, Bacteria,Becker, A.Types of Bacteria ...

methanotroph Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their source of carbon and chemical energy. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to su ...

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

bacteria first isolated and described in 2007 growing on soil and sediment on

Hell's Gate Hells Gate or Hell's Gate or Hell Gate may refer to: Places Africa * Hell's Gate National Park, Kenya Antarctica * Hells Gate Moraine, Victoria Land Asia * Nyalam Town, Tibet * A location in Nampong, Arunachal Pradesh, India * The Darvaza gas c ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Similar organisms have also been isolated from geothermal sites on

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

and

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. A

polyextremophile An extremophile (from Latin ' meaning "extreme" and Greek ' () meaning "love") is an organism that is able to live (or in some cases thrive) in extreme environments, i.e. environments that make survival challenging such as due to extreme temper ...

, these non-motile rods grows optimally at pH between 2.0 and 2.5 and

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

of 60 °C. It is a

ic obligated bacteria that grows at 25% (v/v) of

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...

in air. It is also very dependent on

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

concentrations to grow, optimally at 8% (v/v) in air. Due to its classification in the phylum ''

Verrucomicrobiota Verrucomicrobiota is a phylum of Gram-negative bacteria that contains only a few described species. The species identified have been isolated from fresh water, marine and soil environments and human faeces. A number of as-yet uncultivated species ...

'' and its extreme acidophilic phenotype ''M. infernorum'' is unique between all known

methanotrophs Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their source of carbon and chemical energy. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to su ...

Biology

Genome

It has a single circular chromosome of 2,287,145

base pairs A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

. Under genome analysis it was found that ''M. infernorum'' may use a novel methylotrophic pathway because it encodes

methane monooxygenase Methane monooxygenase (MMO) is an enzyme capable of oxidizing the C-H bond in methane as well as other alkanes. Methane monooxygenase belongs to the class of oxidoreductase enzymes (). There are two forms of MMO: the well-studied soluble form (s ...

enzymes but lacks known genetic modules for methanol and formaldehyde oxidation. All the enzymes required for the Calvin Benson Bassham cycle were identify by genetic analysis.

Metabolism

It has been predicted that ''M. infernorum'' possess most of the key metabolic pathways for the biosynthesis of all amino acids, nucleotides and cofactors, with the sole exception of the

cobalamin Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It ...

cofactor. Genetic studies have shown that the enzymes it uses in several metabolic pathways differs to the ones used by other

methylotroph Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl et ...

s like for example in the biosynthesis of aromatic amino acids, lipoic acid biosynthesis,

urea cycle The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions that produces urea (NH2)2CO from ammonia (NH3). Animals that use this cycle, mainly amphibians and mammals, are called ureotelic. The urea cycle converts highl ...

and in the number and diversity of transporters encoded. The bacteria is able to counteract extreme acidic environments thanks to the presence of various enzymes like

glutamate decarboxylase Glutamate decarboxylase or glutamic acid decarboxylase (GAD) is an enzyme that catalyzes the decarboxylation of glutamate to gamma-aminobutyric acid (GABA) and carbon dioxide (). GAD uses pyridoxal-phosphate (PLP) as a cofactor. The reaction p ...

, glutamate/γ-aminobutyrate antiporter, arginine decarboxylase and an arginine/agmatine antiporter.

References

External links

''Methylacidiphilum infernorum''
on HAMAT (High-quality Automated and Manual Annotation of Proteins) {{Taxonbar, from=Q29887872 Bacteria described in 2007 Verrucomicrobiota Polyextremophiles