Methylococcaceae
Encyclopedia
The Methylococcaceae are a family of bacteria that obtain their carbon and energy from methane
, called methanotroph
s. They comprise the type I methanotrophs, in contrast to the Methylocystaceae
or type II methanotrophs. They belong among the gamma subdivision of the Proteobacteria
, and are typically given their own order.
The Methylococcaceae have internal membranes in the form of flattened discs, perpendicular to the cell wall
. Methane is oxidized to give formaldehyde
, which is fixed by a process called the RuMP cycle. Here formaldehyde is combined with the sugar ribulose
, producing hexulose. This in turn is broken down to produce glyceraldehyde
, which is used to produce new ribulose and other organic compounds. Catabolism does not involve a complete citric acid cycle
.
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
, called methanotroph
Methanotroph
Methanotrophs are bacteria that are able to metabolize methane as their only source of carbon and energy. They can grow aerobically or anaerobically and require single-carbon compounds to survive...
s. They comprise the type I methanotrophs, in contrast to the Methylocystaceae
Methylocystaceae
The Methylocystaceae are a family of bacteria that are capable of obtaining carbon and energy from methane. Such bacteria are called methanotrophs, and in particular the Methylocystaceae comprise the type II methanotrophs, which are structurally and biochemically distinct from the Methylococcaceae...
or type II methanotrophs. They belong among the gamma subdivision of the Proteobacteria
Proteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
, and are typically given their own order.
The Methylococcaceae have internal membranes in the form of flattened discs, perpendicular to the cell wall
Cell wall
The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...
. Methane is oxidized to give formaldehyde
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
, which is fixed by a process called the RuMP cycle. Here formaldehyde is combined with the sugar ribulose
Ribulose
Ribulose is a ketopentose — a monosaccharide containing five carbon atoms, and including a ketone functional group. It has chemical formula 5105. Two enantiomers are possible, D-ribulose and L-ribulose . D-Ribulose is the diastereomer of D-xylulose.Ribulose sugars are composed in the...
, producing hexulose. This in turn is broken down to produce glyceraldehyde
Glyceraldehyde
Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colorless, crystalline solid that is an intermediate compound in carbohydrate metabolism...
, which is used to produce new ribulose and other organic compounds. Catabolism does not involve a complete citric acid cycle
Citric acid cycle
The citric acid cycle — also known as the tricarboxylic acid cycle , the Krebs cycle, or the Szent-Györgyi-Krebs cycle — is a series of chemical reactions which is used by all aerobic living organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats and...
.