Ekaterina Buzun

• BSc (Hons) Biomedical Sciences
• Investigating the mechanism of mucin degradation by the gut microbiota

The thick layer of mucus that protects the intestinal epithelia provides a significant nutrient source for certain gut microbiota. In a healthy gut this process is carefully controlled, whereas in states such as irritable bowel disease (IBD), the mucosal bacteria can damage this protective barrier, thus exacerbating the disease. Little is known about mucus degradation by the gut microbiota, or their nutritional strategies. We investigated enzyme BM03340; from Bacteroides massiliensis, a gut microbe thought to use only mucosal glycans. BM03340 is a family 92 glycoside hydrolase (GH92) targeting α-mannosidic linkages. Data revealed enzyme specificity for α1-3-mannose containing glycans and unlike other characterized GH92s could target substrates where the +1 sugar was substituted, characteristic of plant-derived N-glycans. The study also suggests that the enzyme acts in conjunction with BM03341, a peptide N-glycosidase produced by the species. The data could aid our understanding of the intestinal mucus layer as a microbial niche.

Funding source: Newcastle University

Supervisor: Dr David Cousins