Ruminococcus

Ruminococcus is a genus of bacteria, which occur mainly in the rumen ( rumen ) and in the large intestine of herbivores. It is spherical to oval cocci that occur in pairs or as chains and can only live anaerobically ( obligate anaerobes ). They are gram- positive and have great physiological importance as rumen bacteria in the digestion of cellulose in the digestive tract of herbivores.

Ruminococcus in the rumen

Two species of the genus Ruminococcus flavefaciens and Ruminococcus albus, and the ( non-generic ) Gram-negative bacterium Fibrobacter succinogenes bacteria are most important for the dissolution of cellulose in the rumen.

The important enzyme to decompose cellulose is cellulase. The cellulase is a periplasmic enzyme Fibrobacter, that is, it is located in the periplasm between the two outer cell membranes. Fibrobacter is thus forced to adhere to the Zelullosefibrillen. The Ruminococcus species, however, put this enzyme released into the rumen, the cellulase of this bacterium is an exo-enzyme. The cellulose polysaccharide is then dissolved by the enzyme, the result is glucose. By the bacteria, glucose is taken up again and used by fermentation ( fermentation) as a power source, the re- precipitated fermentation products are again taken up by the animal as a source of energy. The data used by the ruminant products are mainly carboxylic acids. The released from Ruminococcus carboxylic acids are acetic acid ( acetate), and formate, other end products of the fermentation are carbon dioxide and hydrogen. In Fibrobacter there are acetate, formic acid ( formate ) and succinic acid ( succinate ).

System

Current systematics

The genus Ruminococcus in the family of Ruminococcaceae is made to the order Clostridiales in the Department of Firmicutes. From the genus following species are known (as of 2014):

  • Ruminococcus albus Hungate 1957
  • Ruminococcus bromii Moore et al. 1972
  • Ruminococcus callidus Holdeman & Moore 1974
  • Ruminococcus champanellensis Chassard et al. 2012
  • Ruminococcus faecis Kim et al. 2011
  • Ruminococcus flavefaciens Sijpesteijn 1948 ( the type species of the genus )
  • Ruminococcus gauvreauii Domingo et al. 2008
  • Ruminococcus gnavus Moore et al. 1976
  • Ruminococcus lactaris Moore et al. 1976
  • Ruminococcus obeum Moore et al. 1976
  • Ruminococcus torques Holdeman & Moore 1974

Several species that previously belonged to the genus Ruminococcus were assigned to the genus Blautia 2008, this concerns R. hansenii ( now Blautia hansenii ), R. hydrogenotrophicus ( now Blautia hydrogenotrophica ), R. luti ( now Blautia luti ), R. productus ( now Blautia producta ) and R. schinkii ( now Blautia schinkii ).

Synonyms

The two types of R. palustris and R. pasteurii are also not included in this genus. R. pasteurii is now a basionym for Trichococcus pasteurii. R. palustris is a basionym for Trichococcus palustris (another synonym is Lactosphaera pasteurii ). Other synonyms for R. productus Peptostreptococcus productus and Streptococcus are productus, the synonym for R. hansenii Streptococcus hansenii Holdeman and Moore, 1974.

Periplasmic space Exoenzyme
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