It has also been shown that the same bacterial lineages are preferentially enriched in the cellulolytic bacterial community that is associated with wood particles in the gut. In addition to a role in fibre digestion, Symbiotic bacteria in "N. corniger" have also been shown to fix nitrogen at a rate of 0.25-1.0 mg N per colony per hour. This suggests a nitrogen doubling time of 200–500 days making it possible for the whole population of the colony to be replaced once or twice each year.