Archaea Genomes - METHANOSPHAERA STADTMANAE

Methanogenic bacteria are anaerobic, oxygen-intolerant microorganisms There are two types of methanogenic archaea, those belonging to the order Methanosarcinales and those belonging to the orders Methanobacteriales. The energy metabolism of both types of methanogens has been investigated in detail. Methanosphaera stadtmanae ( one of the Methanobacteriales) thrives in the human intestine, where methanol is a product of pectin degradation by Bacteroides species and other anaerobic bacteria. M, stadtmanae is unusual because it is able to grow on methanol and H2 as energy substrates, a property otherwise restricted to members of the Methanosarcinales. It is also remarkable that M. stadtmanae can neither oxidize methanol to CO2 nor reduce CO2 to methane. This organism is also not capable of autotrophic growth on CO2, requiring acetate and CO2 as main carbon sources.

M. stadtmanae has attracted additional interest because it is the first human archaeal commensal whose genome has been sequenced. Such commensals not only are able to survive in the human gastrointestinal tract, which is protected by a highly active immune system, but also stimulate the development of a healthy intestinal epithelium and immune system. In Western countries the increasing number of chronic inflammatory diseases of the intestine (referred to as inflammatory bowel disease) indicates that there is perturbation of the precarious commensal relationship in the human intestine. However, the molecular mechanisms of commensalism are still not fully understood. Studying the genetic information encoded in the small genome of M. stadtmanae may provide clues that will increase our understanding of adaptations of this organism that allow it to live as a commensal

References:

http://www.g2l.bio.uni-goettingen.de/projects/c_proj_mst.html