Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
NCBI PubMed ID: 33043794Publication DOI: 10.1080/19490976.2020.1826761Journal NLM ID: 101495343Publisher: Philadelphia, PA: Taylor & Francis
Correspondence: r.p.singh

nabi.res.in
Institutions: Food and Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, Mohali, India, Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Mohali, India
β-glucans are the dietary nutrients present in oats, barley, algae, and mushrooms. The macromolecules are well known for their immune-modulatory activity; however, how the human gut bacteria digest them is vaguely understood. In this study, Bacteroides uniformis JCM 13288 T was found to grow on laminarin, pustulan, and porphyran. We sequenced the genome of the strain, which was about 5.05 megabase pairs and contained 4868 protein-coding genes. On the basis of growth patterns of the bacterium, two putative polysaccharide utilization loci for β-glucans were identified from the genome, and associated four putative genes were cloned, expressed, purified, and characterized. Three glycoside hydrolases (GHs) that were endo-acting enzymes (BuGH16, BuGH30, and BuGH158), and one which was an exo-acting (BuGH3) enzyme. The BuGH3, BuGH16, and BuGH158 can cleave linear exo/endo-β-1-3 linkages while BuGH30 can digest endo-β-1-6 linkages. BuGH30 and BuGH158 were further explored for their roles in digesting β-glucans and generation of oligosaccharides, respectively. The BuGH30 predominately found to cleave long chain β-1-6-linked glucans, and obtained final product was gentiobiose. The BuGH158 used for producing oligosaccharides varying from degree of polymerization 2 to 7 from soluble curdlan. We demonstrated that these oligosaccharides can be utilized by gut bacteria, which either did not grow or poorly grew on laminarin. Thus, B. uniformis JCM 13288 T is not only capable of utilizing β-glucans but also shares these glycans with human gut bacteria for potentially maintaining the gut microbial homeostasis.
Enzymes, cross-feeding, glycan utilization, gut bacteria, macroalgae
Structure type: homopolymer
Location inside paper: Fig. 2, D, curdlan
Trivial name: glucan, β-1,3-glucan, curdlan, curdlan-type polysaccharide 13140, paramylon, curdlan, laminarin, β-glucan, curdlan, β-(1,3)-glucan, β-(1,3)-glucan, curdlan, curdlan, β-1,3-glucan, paramylon, reserve polysaccharide, b-glucan, β-1,3-D-glucan, laminaran, botryosphaeran, laminaran type β-D-glucan, latiglucan I, pachymaran, Curdlan, zymosan A, β-glucan, curdlan, laminarin, zymosan, zymosan, glucan particles, zymosan, β-(1-3)-glucan, β-(1,3)-glucan, β-(1,3)glucan, pachymaran, D-glucan (DPn)540, pachyman, laminaran, curdlan, zymosan, zymosan, β-(1,3)-glucan, zymosan A, zymosan, β-1,3-glucan, curdlan, β-1,3-glucan, curdlan, β-1,3-glucan, curdlan, pachyman, β-(1,3)-glucan, curdlan, callose, a water-insoluble β-(1→3)-glucan, fermentum β-polysaccharide, water-insoluble glucan, alkali-soluble β-glucan (PeA3), alkali-soluble polysaccharide (PCAP), callose, laminarin
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, lipophosphoglycan, glycoprotein, LPG, glucan, polysaccharide, glycoside, β-glucan, β3-glucan, cell wall glucan
Contained glycoepitopes: IEDB_1397514,IEDB_142488,IEDB_146664,IEDB_153543,IEDB_158555,IEDB_161166,IEDB_2278476,IEDB_2278477,IEDB_558869,IEDB_857743,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, NMR-2D, PCR, DNA sequencing, SDS-PAGE, TLC, ELISA, alkaline hydrolysis, enzymatic digestion, affinity chromatography, MALDI-TOF, cloning, cell growth, enzymatic assay, gene expression, DNA extraction, spectrophotometry, Bradford method, centrifugation, DEPT-135, BLASTp, dinitrosalicylic acid (DNS) method
Enzymes that release or process the structure: BuGH3 (glycoside hydrolase), BuGH16 (glycoside hydrolase), BuGH158 (glycoside hydrolase)
Related record ID(s): 41552, 41631, 41632, 43323, 45734, 47152, 47304, 49279, 49282, 50035, 50085, 50617, 50648, 50654, 50671, 50861
NCBI Taxonomy refs (TaxIDs): 511Reference(s) to other database(s): GTC:G51056AN, GlycomeDB:
157, CCSD:
50049, CBank-STR:4225, CA-RN: 51052-65-4, GenDB:FJ3380871.1
Show glycosyltransferases
There is only one chemically distinct structure: