Methanosarcina
Encyclopedia
Methanosarcina are the only known anaerobic
methanogens to produce methane using all three known metabolic pathways for methanogenesis
. Most methanogens make methane
from carbon dioxide
and hydrogen
gas. Some others utilize acetate
in the acetoclastic pathway. In addition to these two pathways, species of Methanosarcina can also metabolize methylated one-carbon compounds through methylotroph
ic methanogenesis
. Such one-carbon compounds include methylamines, methanol
, and methyl thiols. Thus species of Methanosarcina are the most diverse methanogens in terms of physiology
. They are found in diverse environments, including trash dumps, sewage heaps, deep sea vents, deep subsurface groundwater, and even in the gut of many different ungulates, including cows, sheep, goats, and deer. Methanosarcina have even been found in the human digestive tract too. Methanosarcina are also unique in that they have been found to grow in colonies and even show primitive cellular differentiation. Both M. acetivorans and M. mazei have been found to have exceptionally large genome
s. As of August 2008, M. acetivorans possessed the largest sequenced archaeal genome at 5,751,492 bp. Slightly smaller is the genome of M. mazei, with 4,096,345 bp.
Anaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...
methanogens to produce methane using all three known metabolic pathways for methanogenesis
Methanogenesis
Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Organisms capable of producing methane have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with...
. Most methanogens make methane
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...
from carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
gas. Some others utilize acetate
Acetate
An acetate is a derivative of acetic acid. This term includes salts and esters, as well as the anion found in solution. Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In...
in the acetoclastic pathway. In addition to these two pathways, species of Methanosarcina can also metabolize methylated one-carbon compounds through methylotroph
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 bonds, such as dimethyl ether and dimethylamine...
ic methanogenesis
Methanogenesis
Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Organisms capable of producing methane have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with...
. Such one-carbon compounds include methylamines, methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
, and methyl thiols. Thus species of Methanosarcina are the most diverse methanogens in terms of physiology
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
. They are found in diverse environments, including trash dumps, sewage heaps, deep sea vents, deep subsurface groundwater, and even in the gut of many different ungulates, including cows, sheep, goats, and deer. Methanosarcina have even been found in the human digestive tract too. Methanosarcina are also unique in that they have been found to grow in colonies and even show primitive cellular differentiation. Both M. acetivorans and M. mazei have been found to have exceptionally large genome
Genome
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....
s. As of August 2008, M. acetivorans possessed the largest sequenced archaeal genome at 5,751,492 bp. Slightly smaller is the genome of M. mazei, with 4,096,345 bp.
External links
- Putting Life's Puzzle Together from Astrobiology Magazine (May 17, 2006)
- Methanosarcina from The Microbial Biorealm at Kenyon College
- Comparative Analysis of Methanosarcina Genomes (at DOE'sUnited States Department of EnergyThe United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
IMG systemIntegrated Microbial Genomes SystemThe Integrated Microbial Genomes is a genome browsing and annotation system developed by the DOE-Joint Genome Institute. IMG contains all the draft and complete microbial genomes sequenced by the DOE-JGI integrated with other publicly available genomes...
) - Methanosarcina Genome Projects (from Genomes OnLine Database)