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Extraction and characterization of dextran from Leuconostoc pseudomesenteroides YB-2 isolated from mango juice

Ye, Guangbin, Li, Genliang, Wang, Changli, Ling, Bo, Yang, Ruirui, Huang, Suoyi
Carbohydrate polymers 2019 v.207 pp. 218-223
Escherichia coli, Fourier transform infrared spectroscopy, Leuconostoc pseudomesenteroides, Staphylococcus aureus, dextran, exopolysaccharides, gas chromatography, glucose, mango juice, minimum inhibitory concentration, molecular weight, nuclear magnetic resonance spectroscopy, scanning electron microscopy, water holding capacity, water solubility
An exopolysaccharide (EPS)-producing strain of YB-2 isolated from mango juice was identified as Leuconostoc pseudomesenteroides. The molecular weight (Mw) of this EPS was 7.67×105 Da. Gas chromatography (GC) analysis confirmed the presence of only glucose monomers. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectra displayed the glucan nature of the EPS with 96.8% α-(1→6) and 3.2% branching α-(1→3) linkages. Scanning electron microscopy (SEM) showed smooth surfaces and compact structure. The water solubility index (WSI) and water-holding capacity (WHC) of dextran were 97.48±2.46% and 287.51±7.93%, respectively. The rheological analysis of dextran elucidated a non-Newtonian pseudoplastic behavior. The dextran revealed an inhibitory activity against Escherichia coli and Staphylococcus aureus with minimal inhibitory concentrations (MIC) of 2.0 mg/mL and 3.0 mg/mL, respectively.