Methylococcaceae
Micrograph of Methylococcus capsulatus
Methylococcaceae form a family of Proteobacteria and are in addition to the Crenotrichaceae the only member of the order Methylococcales. They are among the methanotrophs, they are capable of using methane as the sole carbon source for the construction of the cell substance ( assimilation ) and the energy gain to grow ( by oxidation to methanol). Through the utilization of the greenhouse gas methane they are ecologically very important.
The cells are rod - or kokkenförmig. Partial occur chains of cells. Some species form cystenförmige corpuscles as resting stages.
Metabolism
The Methylococcaceae among the methanotrophic bacteria, a subset of methylotrophic bacteria. Methylotrophic shall be recovered in a position to compounds that do not have C -C bonds. In these molecules, only a carbon atom (e.g., methanol, methane ) is either included or not a carbon atom directly connected with one another. The methanotrophs can use thereof methane and methanol. The methylotrophs, however, could also use some more connections without direct carbon-carbon bonds, such as Trimethylamine, methylamine, and dimethylamine. The methanotrophs differ continued use of the methylotrophs by the possession of the enzyme methane monooxygenase (MMO ) and the ability of CO2. Using the enzyme MMO methane is oxidized into methanol and transmit the energy obtained in the respiratory chain and ATP produced.
Bacteria of the genera Methylobacter, Methylococcus and Methylosphaera are in addition to fix nitrogen in a position
Position within the methylotrophs
The methanotrophic bacteria are divided on the basis of different characteristics, such as cell structure and metabolism into three groups, Group I, II and X. The Methylococcaceae form the group I use Einkohlenstoffverbindungen in metabolism using the Ribulosemonophosphatweg. In the metabolism of group II carbon is fixed via the serine pathway. Types of Methylocystaceae family form this group. Another distinguishing feature is the shape of the inner membranes. In group I, they are arranged in stacks, in type II, however, they run parallel to the outer cell membrane. The group X is again a subgroup of the group I. The special feature of these bacteria is the ability to fix in addition to methane and CO2. These include the genera Methylococcus and Methylocaldum.
Optional methylotrophic bacteria are not dependent on Einkohlenstoffverbindungen, but they can additionally use, such as different types of Arthrobacter, Pseudomonas, Micrococcus and Bacillus.
System
The bacterium Crenothrix polyspora, also known by the name of thread fountain is also oxidize methane in the situation. Analyzes of the 16S rRNA sequence show a high affinity to the type Methylobacter psychrophilus. This type is guided by NCBI in the counting to the same order Crenotrichaceae family.
Currently, the Methylococcaceae of the following genera:
- Methylobacter Bowman et al. 1993
- Methylocaldum Bodrossy et al. 1998
- Methylococcus Foster and Davis 1966
- Methylogaea Geymonat et al. 2011
- Methylohalobius Heyer et al. 2005
- Methylomicrobium Bowman et al. 1995
- Methylomonas (ex Leadbetter 1974) Whittenbury & 1984 War
- Methylosarcina Wise et al. 2001
- Methylosoma Rahalkar et al. 2007
- Methylosphaera Bowman et al. 1998
- Methylothermus Tsubota et al. 2005
- Methylovulum Iguchi et al. 2011