Degradation of complex arabinoxylans by human colonic Bacteroidetes

• Published in: Nature communications Vol. 12; no. 1; p. 459
• Main Authors: Pereira, Gabriel V., Abdel-Hamid, Ahmed M., Dutta, Soumajit, D’Alessandro-Gabazza, Corina N., Wefers, Daniel, Farris, Jacob A., Bajaj, Shiv, Wawrzak, Zdzislaw, Atomi, Haruyuki, Mackie, Roderick I., Gabazza, Esteban C., Shukla, Diwakar, Koropatkin, Nicole M., Cann, Isaac
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19-01-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 38; 38/22; 38/23; 38/39; 38/70; 38/77; 38/88; 38/90; 38/91; 45; 631/326/2565/2134; 631/326/2565/547; 82/16; 82/29; 82/83; Accumulation; Acids; Arabinoxylans; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Bacterial Proteins - metabolism; Bacterial Proteins - ultrastructure; Bacteroides; Bacteroides - enzymology; Bacteroides - genetics; Bacteroidetes; Biodegradation; Colon - microbiology; Coumaric Acids - metabolism; Crystallography, X-Ray; Degradation; Dietary fiber; Dietary Fiber - metabolism; Enzyme Assays; Esterases; Esterases - genetics; Esterases - isolation & purification; Esterases - metabolism; Esterases - ultrastructure; Ferulic acid; Gastrointestinal Microbiome - physiology; Gene clusters; Humanities and Social Sciences; Humans; Immunomodulation; Intestinal Mucosa - microbiology; Molecular Dynamics Simulation; multidisciplinary; Multigene Family - genetics; Phenols; Polysaccharides; Saccharides; Science; Science (multidisciplinary); Substrate Specificity; Xylans - chemistry; Xylans - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-20737-5

Some Bacteroidetes and other human colonic bacteria can degrade arabinoxylans, common polysaccharides found in dietary fiber. Previous work has identified gene clusters (polysaccharide-utilization loci, PULs) for degradation of simple arabinoxylans. However, the degradation of complex arabinoxylans (containing side chains such as ferulic acid, a phenolic compound) is poorly understood. Here, we identify a PUL that encodes multiple esterases for degradation of complex arabinoxylans in
Bacteroides
species. The PUL is specifically upregulated in the presence of complex arabinoxylans. We characterize some of the esterases biochemically and structurally, and show that they release ferulic acid from complex arabinoxylans. Growth of four different colonic Bacteroidetes members, including
Bacteroides intestinalis
, on complex arabinoxylans results in accumulation of ferulic acid, a compound known to have antioxidative and immunomodulatory properties.
Human gut bacteria can degrade arabinoxylans, polysaccharides found in dietary fiber. Here, Pereira et al. identify a bacterial gene cluster encoding esterases for degradation of complex arabinoxylans. The action of these enzymes results in accumulation of ferulic acid, a phenolic compound with antioxidative and immunomodulatory properties.