title: Characterization of an exopolysaccharide produced by Lactobacillus plantarum YW11 isolated from Tibet Kefir.
abstract: An exopolysaccharide (EPS)-producing strain YW11 isolated from Tibet Kefir was identified as Lactobacillus plantarum, and the strain was shown to produce 90 mgL(-1) of EPS when grown in a semi-defined medium. The molecular mass of the EPS was 1.1 × 10(5)Da. The EPS was composed of glucose and galactose in a molar ratio of 2.71:1, with possible presence of N-acetylated sugar residues in the polysaccharide as confirmed by NMR spectroscopy. Rheological studies showed that the EPS had higher viscosity in skim milk, at lower temperature, or at acidic pH. The viscous nature of the EPS was confirmed by observation with scanning electron microscopy that demonstrated a highly branched and porous structure of the polysaccharide. The atomic force microscopy of the EPS further revealed presence of many spherical lumps, facilitating binding with water in aqueous solution. The EPS had a higher degradation temperature (287.7°C), suggesting high thermal stability of the EPS.
authors: Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing, China; School of Biological and Agricultural Engineering, Jilin University, Changchun, China.
authors: Ji
authors: J
authors: Wang
authors: Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing, China.
authors: Xiao
authors: X
authors: Zhao
authors: Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing, China.
authors: Zheng
authors: Z
authors: Tian
authors: Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing, China.
authors: Yawei
authors: Y
authors: Yang
authors: Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing, China; School of Biological and Agricultural Engineering, Jilin University, Changchun, China. Electronic address: yangzhennai@163.com.
authors: Zhennai
authors: Z
authors: Yang
mesh_terms: D043302:Cultured Milk Products / Q000737:chemistry / Q000382:microbiology*; D048191:Lactiplantibacillus plantarum / Q000737:chemistry* / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial / Q000737:chemistry*
chemical_list: D011135:Polysaccharides, Bacterial
keywords: Calcium chloride (PubChem CID: 21226093); Exopolysaccharide; Fructose (PubChem CID: 5984); Glucose (PubChem CID: 79025); Glucuronic acid (PubChem CID: 444791); Glycerol (PubChem CID: 753); Lactobacillus plantarum; Phenol (PubChem CID: 996); Rhamnose (PubChem CID: 25310); Rheology; Sodium chloride (PubChem CID: 5234); Sodium nitrate (PubChem CID: 24268); Structural characterization; Sulfuric acid (PubChem CID: 1118); Trifluoroacetic acid (PubChem CID: 6422)