The mucin-degradation strategy of Ruminococcus gnavus: The importance of intramolecular trans-sialidases

Emmanuelle H Crost, Louise E Tailford, Marie Monestier, David Swarbreck, Bernard Henrissat, Lisa C. Crossman, Nathalie Juge

Research output: Contribution to journalArticlepeer-review

90 Citations (Scopus)
10 Downloads (Pure)


We previously identified and characterized an intramolecular trans-sialidase (IT-sialidase) in the gut symbiont Ruminococcus gnavus ATCC 29149, which is associated to the ability of the strain to grow on mucins. In this work we have obtained and analyzed the draft genome sequence of another R. gnavus mucin-degrader, ATCC 35913, isolated from a healthy individual. Transcriptomics analyses of both ATCC 29149 and ATCC 35913 strains confirmed that the strategy utilized by R. gnavus for mucin-degradation is focused on the utilization of terminal mucin glycans. R. gnavus ATCC 35913 also encodes a predicted IT-sialidase and harbors a Nan cluster dedicated to sialic acid utilization. We showed that the Nan cluster was upregulated when the strains were grown in presence of mucin. In addition we demonstrated that both R. gnavus strains were able to grow on 2,7-anyhydro-Neu5Ac, the IT-sialidase transglycosylation product, as a sole carbon source. Taken together these data further support the hypothesis that IT-sialidase expressing gut microbes, provide commensal bacteria such as R. gnavus with a nutritional competitive advantage, by accessing and transforming a source of nutrient to their own benefit.
Original languageEnglish
Pages (from-to)302-312
JournalGut Microbes
Issue number4
Early online date25 May 2016
Publication statusPublished - 2016


  • Intestinal mucin
  • gut bacteria
  • glycoside hydrolase
  • sialic acid
  • intramolecular trans-sialidase
  • mucin glycans
  • Ruminococcus gnavus
  • carbohydrate-active enzyme (CAZyme)
  • carbohydrate binding module (CBM)
  • coding DNA sequence (CDS)
  • glycoside hydrolase (GH)
  • gastrointestinal (GI)
  • glucose (Glc)
  • intramolecular trans-sialidase (IT-sialidase)
  • 4-methylumbelliferyl (MU)
  • N-acetylneuraminic acid (Neu5Ac)
  • open reading frame (ORF)
  • purified pig gastric mucin (pPGM)
  • sialyllactose (SL)

Cite this