Title: Archaea - Wikipedia
Headings: Archaea
Archaea
Contents
Classification
Early concept
Classification
Cladogram
Taxonomy
Concept of species
Origin and evolution
Comparison with other domains
Relationship to bacteria
Relation to eukaryotes
Morphology
Structure, composition development, and operation
Cell wall and flagella
Membranes
Metabolism
Genetics
Gene transfer and genetic exchange
Archaeal viruses
Reproduction
Behavior
Communication
Ecology
Habitats
Role in chemical cycling
Interactions with other organisms
Mutualism
Commensalism
Significance in technology and industry
See also
References
Further reading
External links
General
Classification
Genomics

Content: They are part of the microbiota of all organisms. In the human microbiome, they are important in the gut, mouth, and on the skin. Their morphological, metabolic, and geographical diversity permits them to play multiple ecological roles: carbon fixation; nitrogen cycling; organic compound turnover; and maintaining microbial symbiotic and syntrophic communities, for example. No clear examples of archaeal pathogens or parasites are known. Instead they are often mutualists or commensals, such as the methanogens (methane-producing strains) that inhabit the gastrointestinal tract in humans and ruminants, where their vast numbers aid digestion. Methanogens are also used in biogas production and sewage treatment, and biotechnology exploits enzymes from extremophile archaea that can endure high temperatures and organic solvents .