title: Purification and partial elucidation of the structure of an antioxidant carbohydrate biopolymer from the probiotic bacterium Bacillus coagulans RK-02.
abstract: An exopolysaccharide (EPS) was isolated from Bacillus coagulans RK-02 and purified by size exclusion chromatography. The purified, homogeneous EPS had an average molecular weight of ∼3 × 10⁴ Da by comparison with FITC-labeled dextran standards. In vivo evaluations showed that, like other reported polysaccharides, this EPS displayed significant antioxidant activity. FTIR spectroscopy analysis showed the presence of hydroxy, carboxy, and α-glycosidic linkages and a mannose residue. GC analysis indicated that the EPS was a heteropolymer composed of glucose, mannose, galactose, glucosamine, and fucose as monomeric constituent units. Partial elucidation of the structure of the carbohydrate biopolymer based on GC-MS and NMR analysis showed the presence of two unique sets of tetrasaccharide repeating units that have 1→3 and 1→6 glycosidic linkages. This is also the first report of a Gram-positive bacterial polysaccharide with both fucose as a sugar monomer and 1→3 and 1→6 glycosidic linkages in the molecular backbone.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Kharagpur-721302, West Bengal, India.
authors.forename: Vidya P
authors.initials: VP
authors.lastname: Kodali
authors.forename: Ramu S
authors.initials: RS
authors.lastname: Perali
authors.forename: R
authors.initials: R
authors.lastname: Sen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D001407:Bacillus / Q000737:chemistry*; D001704:Biopolymers / Q000032:analysis / Q000097:blood; D001713:Biphenyl Compounds / Q000494:pharmacology; D002240:Carbohydrate Sequence; D016166:Free Radical Scavengers / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005690:Galactose / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D008358:Mannose / Q000032:analysis; D051379:Mice; D008970:Molecular Weight; D010851:Picrates / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D019936:Probiotics / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013482:Superoxide Dismutase / Q000032:analysis
chemical_list: D000975:Antioxidants; D001704:Biopolymers; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D011135:Polysaccharides, Bacterial; C562118:exopolysaccharide biopolymer, Bacillus coagulans; C004931:1,1-diphenyl-2-picrylhydrazyl; D013482:Superoxide Dismutase; D008358:Mannose; D005690:Galactose